This mobile-first quick reference guide is designed to help you:
A11y: Accessibility
IAAP: International Association of Accessibility Professionals
CPACC: Certified Professional in Accessibility Core Competencies
BoK: Body of Knowledge
This guide covers the key topics in the IAAP CPACC Body of Knowledge. You could read the guide from "front-to-back" in around an hour.
But, it's more likely that you will want to dip in and out of topics as you study the CPACC Body of Knowledge, or use it as a reference later.
There are two ways to move around:
Table of contents: select the Table of contents button to see all domains and topics. The current topic is highlighted so you always know where you are in the framework. Use it to jump to any topic directly.
Sequential navigation: use the next and previous buttons to move through the guide topic by topic. Each domain page also links directly to its topics.
The guide is organised into the 3 domains of the BoK. Each domain contains a set of topics. Many topics use an accordion to group related subtopics. Select a tab to expand a panel and read the content. The page scrolls automatically to show the title of the expanded panel at the top of the screen.
For longer topics, there’s a back-to-top button to save you scrolling. A backlink at the top of each topic takes you back to the domain page.
The guide is designed primarily for mobile use, but it works well on any device. The layout, text size, and navigation are all optimised for a small screen. If you are studying on the go, it should feel at home on your phone.
Disabilities, challenges and assistive technologies.
Categories and characteristics of disabilities, associated barriers and solutions.
Visual disabilities include:
Each condition has distinct access implications.
A person who is blind receives no functional visual information. They rely on non-visual means to access content and navigate the environment.
Example
A blind person using a computer depends on a screen reader to convert text into speech or braille output. Any visual information must have a text alternative for the assistive tools to be useful.
Key point
Legal and medical definitions of blindness vary. "Legally blind" often includes people with some residual vision. In accessibility practice, assume that a screen reader user may have no usable vision.
A person with low vision has partial sight that cannot be fully corrected by glasses or surgery. They may use their vision alongside assistive tools, often with significant magnification.
Example
Someone with low vision might enlarge the text in their browser to 300%. They might also use high contrast mode or rely on a screen magnifier. They often use both vision and technology simultaneously, making layout and spacing critical.
Key point
Many low vision users do not use screen readers at all. Visual presentation matters more for this group.
Colour vision deficiency reduces the ability to distinguish between certain colours. The most common form impacts red-green discrimination. But this condition exists on a spectrum.
Example
A chart with only red and green lines is hard to read for those with red-green colour vision deficiency. Adding distinct line patterns or labels solves the problem.
Key point
Colour vision deficiency is far more prevalent than most designers assume. It affects approximately 8% of men of European descent. It is not the same as seeing only in grey tones. Most people with CVD see colour, but not as someone without the deficiency does.
Auditory disabilities include:
Each of these conditions requires different access strategies.
A person who is deaf has no functional hearing. They can only understand audio content through visual options, such as captions, transcripts or sign language interpretation.
Example
A deaf person watching a video without captions receives no audio. Dialogue, sound effects and tone of voice are all inaccessible unless provided in text or visual form.
Key point
Many Deaf people (with a capital D) identify with Deaf culture. They may prefer sign language over written text. For some, reading in a written language is a second-language skill, so captions alone may not be enough.
A person who is hard of hearing has some degree of hearing loss. They may use residual hearing combined with hearing aids, captions or other strategies.
Example
In a meeting room with poor acoustics, a person with hearing aids may miss critical dialogue. A loop system or real-time captions gives them equal access to the conversation.
CAPD affects how the brain interprets sound. While the ear works normally, the person struggles to discern speech. This is especially true in noisy environments.
Example
A person with CAPD in a busy café may hear someone talking but be unable to decode what is being said.
Key point
CAPD is easily overlooked because the person "passes" a standard audiological test. Their difficulty is neurological, not peripheral. They are often misunderstood as being inattentive or having a language difficulty.
Deafblindness is the combination of both hearing and vision loss. But it is more than the sum of its parts. Since neither sense fully compensates for the loss of the other, unique barriers to communication arise. People who are Deafblind need tactile communication and other accessible channels.
Example
A person who is Deafblind may use a refreshable braille display connected to a screen reader. Text is the only format that reaches them. So, alt text, captions and transcripts are all essential, not supplementary.
Key point
Most people identified as Deafblind have some residual vision or hearing. Complete absence of both senses is uncommon. Further, Deafblindness exists on two separate spectra. So, the degree of loss in each sense determines the specific access needs.
Speech and language disabilities affect how people speak or understand spoken words. These problems can be small like pronunciation differences, or big, like not being able to speak at all. They can make it hard to use systems and situations that need talking.
Organic speech sound disorders have a physical cause. These causes include differences in body structure, brain problems or issues with the senses that change how speech sounds are made.
Example
A person with dysarthria from cerebral palsy may have speech that is hard to understand. Voice recognition software made for normal speech often cannot understand what they say correctly.
Key point
“Organic” shows there is a clear physical cause. This makes these disorders different from functional speech sound disorders, where no physical cause can be found.
Functional speech sound disorders affect how people make sounds when they talk, even though there is no clear physical reason. Sounds may be changed, left out or mixed up, and these problems might get better or stay the same over time.
Example
A child who often replaces “r” with “w” (saying “wabbit” instead of “rabbit”) has a functional articulation disorder. Their speech organs work fine, but they have learned to say sounds in a different way than usual.
Mutism means not speaking. It can be selective, which means a person talks in some situations but not in others, or it can be total, meaning the person does not speak at all. Mutism can happen because of mental health, brain problems or other reasons.
Example
A child with selective mutism talks easily at home but does not speak at school. Tools like a tablet that uses pictures and symbols can help them take part.
Key point
Selective mutism is an anxiety disorder, not a choice or stubbornness. People with selective mutism can usually speak well in other situations and should not be thought to have problems with thinking or language.
Aphasia is a language problem people get after a stroke or brain injury. It can make it hard to speak, understand, read or write.
Example
A person with Broca’s aphasia knows what they want to say but cannot speak fluently. They might use single words or short phrases, and they can still understand others well.
Key point
Aphasia makes it hard for a person to use language, but it does not change how smart they are. A person with severe aphasia can think clearly but cannot speak or write their thoughts.
Mobility and body function disabilities affect how a person moves, controls their body and how their body works. These disabilities can make it hard to use places and tools made for people with usual physical abilities.
Problems with hand and finger skills make it hard to do the precise movements needed to use a keyboard, mouse, touchscreen or small buttons.
Example
A person with Parkinson’s disease may have trouble clicking small buttons or typing well on a regular keyboard. Using switch access, voice control or bigger touch targets can help them use devices on their own again.
Key point
Problems with small movements are often hidden. A person may seem fine until they try a task that needs careful control. Many people who use keyboard navigation and switch access have problems moving their hands, not seeing.
Ambulation disabilities affect the ability to walk or move around. They can include needing help like canes or wheelchairs, or not being able to walk at all.
Example
A person using a wheelchair cannot enter a building if steps block the entrance. A ramp or flat entrance lets everyone enter easily without needing help or going around.
Muscle fatigue problems make muscles get tired quickly or without warning. A person might be able to do a task at first but then cannot keep doing it.
Example
A person with multiple sclerosis might be able to type for a short time but feels weaker if they keep typing. Using keyboard shortcuts, voice input and tasks that need fewer keystrokes can make typing easier.
Key point
Disabilities caused by tiredness come and go. A person’s ability one day might be different on another day. Designing for efficiency and reducing repetitive actions benefits this group significantly.
Designing to save time and cut down on doing the same tasks again helps this group a lot.
Example
An ATM that is placed at a height easy for standing adults to reach is hard to use for people sitting down or who are very short. Controls that can be moved up and down or placed lower solve this problem.
Key point
People often ignore body size and shape when talking about disability and accessibility. The ideas behind universal design talk about this clearly, especially in the “Size and Space for Approach and Use” principle.
Cognitive disabilities change how people think, understand, remember and share information. They include many kinds of disabilities and are often the least helped by regular accessibility efforts.
Intellectual disabilities cause big challenges with thinking and daily skills. They affect learning, reasoning, solving problems and doing everyday tasks on your own.
Example
A person with an intellectual disability using a government benefits website may have trouble with hard sentences, difficult words, or many steps. Using simple words, clear instructions and easy steps helps them get access more easily.
Key point
“Intellectual disability” is the better term to use now instead of older words like the “R” word (look it up). The words we use have changed a lot, and it is important to be accurate.
Dyslexia is a learning disability that makes it hard to read and spell words correctly and smoothly. It happens because of how the brain works, is not connected to how smart someone is, and can affect people of all different thinking levels.
Example
A very smart adult with dyslexia may read slowly, often lose their place or mix up letters that look alike. Tools like text-to-speech, adjustable line spacing and special fonts for dyslexia make reading easier.
Key point
Dyslexia is not a problem with your eyes. Letters are not actually moving or flipped around. It is a difference in how the brain handles phonemes that makes it harder to turn written letters into spoken words.
Dyscalculia is a learning disability that makes it hard to understand numbers, do math problems and learn math ideas. It is like dyslexia but for numbers.
Example
A person with dyscalculia might not be able to tell which of two prices is bigger or have trouble counting change at a checkout. Showing totals clearly and not depending on mental math makes it easier for them.
ADHD means having ongoing problems with paying attention, being very active and acting without thinking. These problems make it hard to focus, plan tasks and control behaviour.
Example
Someone with ADHD filling out a long online form might lose focus halfway, miss important fields or get distracted by animations and moving content. Reducing distractions and saving progress automatically helps them finish the task.
Key point
ADHD shows up in different ways in different people and situations. The type without hyperactivity, called inattentive ADHD, is often missed, especially in women and girls. People might think they are just not interested or not trying hard.
Autism spectrum disorders affect how people communicate, process senses and change their behaviour. These effects can be very different for each person. Problems with access are often related to senses or communication, not just thinking skills.
Example
A person with autism might feel upset by sounds that play automatically, flashing pictures or sudden changes on the screen. Using a design that is steady and easy to predict, and letting users control these sensory features, helps reduce stress and makes it easier to use.
Key point
Autism is a spectrum. Some autistic people need a lot of help, while others can live on their own. The term “High-functioning” is debated in the autistic community because it often ignores the need for support while hiding true ability.
NVLD makes it hard to understand things without words, like space and shapes, patterns, facial expressions, tone of voice and tasks that involve seeing and using space.
Example
Someone with NVLD might be good at reading and talking but have trouble with maps, diagrams or understanding charts. Using clear verbal explanations instead of or along with pictures helps them understand better.
Key point
NVLD is often called the “inverse of dyslexia”. Strong talking and reading skills can hide the disability, so it is often missed, especially when doing well in verbal school subjects makes it seem like there is no problem.
Seizure disorders cause sudden changes in the brain’s electrical activity. The kind of seizures and what causes them to decide which access barriers matter in both digital and physical places.
General seizure disorders can lead to various episodes. These can range from brief staring spells to convulsions. Often, these episodes don’t have clear triggers in the person’s environment.
Example
A person with generalised epilepsy may have a tonic-clonic seizure without any warning or clear cause. Their needs are more about staying physically safe, having good communication and avoiding too much information at once than about limiting what they can see or hear.
Photosensitive epilepsy happens when flashing or flickering images cause a seizure. Pictures that flash more than three times every second can trigger a seizure in people who are affected.
Example
A fast flashing ad on a news website could cause a seizure in someone with photosensitive epilepsy. This is why accessibility rules limit how fast things can flash and block some patterns.
Key point
Photosensitive epilepsy affects a small group of people with epilepsy. When it triggers a seizure, the effects are immediate and serious. This is one of the few accessibility problems that can cause real physical harm.
Psychological disabilities affect how people think and act, making it hard for them to take part in activities. These disabilities often come and go, change over time and are not easy to see. They are also often left out of talks about accessibility.
Anxiety disorders cause strong, ongoing fear or worry that gets in the way of daily life. They can make new, hard or important digital tasks much harder to do.
Example
Someone with strong social anxiety might not be able to do a task that needs live talking or phone calls. Providing options like texting or delayed replies makes things easier. It allows someone to avoid directly stating they have social anxiety.
Key point
Anxiety disorders are the most common mental health problems in the world. Design choices that cause uncertainty, unclear ways to fix mistakes, or very important actions that cannot be undone affect people with anxiety more than others.
Mood disorders, like depression and bipolar disorder, affect a person’s motivation, energy, focus and ability to keep working on tasks for a long time.
Example
During a depressive episode, a person might struggle to finish tasks that have many steps. They may also find it hard to remember information between sessions or to understand difficult text. Saving progress, making things easier to think about, and letting tasks be started again easily all help.
Key point
Mood disorders happen in episodes, so a person’s ability to function changes. A plan that helps them when they feel well might not work when they are having an episode. Showing information step-by-step and making tasks easy help keep access reliable.
Psychotic disorders, like schizophrenia, can change how a person sees and thinks. They can make it hard to tell what is real and what is not, which can make it difficult to handle tricky or confusing situations.
Example
A person in a psychotic episode may misinterpret unclear interface messages. They may find it tough to spot key information or follow step-by-step instructions. Using clear, simple language and easy-to-use interfaces helps reduce confusion.
Key point
Psychotic disorders are some of the most misunderstood disabilities. People often overlook this when discussing accessibility. The ideas that support individuals with intellectual disabilities and dementia also benefit those with psychotic disorders.
Many people have more than one disability at the same time. When this happens, the challenges they face can be bigger and harder to solve than with just one disability.
Characterising and differentiating between theoretical models of disability, including the strengths and weaknesses of their underlying assumptions.
Disability is seen as a health condition that affects an individual's body. It's considered a problem of diagnosis, treatment, and, if possible, cure.
Example
A clinician assessing a person in a wheelchair focuses on the underlying diagnosis. Then they consider what medical intervention might restore mobility.
Key point
The medical model isn't wrong about biology. But it's limited to treating the person's body as the only site of the problem. It ignores inaccessible environments and social barriers.
Disability is created by the gap between a person's body or mind and an environment that wasn't designed to include them. The barrier is in the world, not the person.
Example
A wheelchair user isn't disabled by their legs. They are disabled by buildings with stairs and no ramps. Remove the stairs, and the disability disappears.
Key point
Critics argue that the social model downplays the real limitations caused by impairments. They assert that not every barrier is architectural or attitudinal.
Disability comes from a mix of health issues, personal experiences and social or physical environments. It is biological, personal and contextual.
Example
The model shows how these three factors work together to produce functional outcomes. The World Health Organization (WHO) used this model to develop its International Classification of Functioning, Disability and Health (ICF) framework.
Key point
This model supports the ICF framework. Understanding this link explains why the ICF is seen as more complete than just medical or social views.
Disability means reduced ability to work and earn money, which can make a person a cost to productivity and welfare systems.
Example
Insurance and benefits systems often define disability based on how much a condition hinders work. Someone who can work part-time is assessed differently from someone who can't work at all.
Key point
This model influences policy and funding decisions. It often views disability as an economic burden rather than a matter of participation and rights.
Disability is a practical issue that technology and design can address. The goal is to provide functional solutions, not to debate the cause of the barrier.
Example
An engineer creating a screen reader isn't questioning if blindness is a medical or social issue. They are building a tool for independent access to information.
Key point
This model drives much of the development of assistive technology. It is useful, but it can depoliticise disability by treating it as a technical challenge and ignoring systemic change.
Disability is a valued part of human diversity and cultural identity. It is not a flaw to fix but a trait that influences experiences and communities.
Example
Many Deaf people do not see deafness as a disability. They belong to a linguistic and cultural community linked by sign language, shared history and unique norms.
Key point
The Deaf community is a prime example, but the model also appears in autistic self-advocacy. Not everyone with a condition is identified in this way, and views differ widely.
Disabled people are often seen as objects of pity who rely on the kindness of non-disabled individuals. Support is viewed as generosity rather than a right.
Example
Fundraising campaigns sometimes depict disabled children as tragic figures needing rescue. This is an example of the charity model at work.
Key point
Disability rights advocates criticise this view. They argue that it presents disabled people as passive recipients, not as citizens with rights. Yet, this perspective remains common in public messaging and fundraising.
Assistive Technologies (AT) and adaptive strategies.
Identifying appropriate assistive technologies and adaptive strategies for permanent, temporary, and situational disabilities, including:
Assistive technology for people with vision problems replaces or adds to visual information using touch, sound or clearer images so they can access content and places on their own.
In the real world, assistive technology for people with visual disabilities uses tools that give touch or sound information instead of visual signals.
Example
A blind person uses a long cane to find obstacles when walking and depends on raised strips on the ground at crosswalks to know where it is safe to cross. These are physical tools that help with accessibility.
Key point
Guide dogs are well known, but they are not always available or suitable. Solutions for physical spaces should not rely only on guide dogs for access.
In the ICT environment, assistive technology for visual disabilities includes screen readers, screen magnifiers, braille displays and settings for high contrast or colour adjustments.
Example
A blind person uses a screen reader like NVDA or JAWS to listen to web content read aloud. A person with low vision uses built-in magnification to make the display bigger and easier to see. Both need the content to be organised in an accessible way.
Key point
Screen readers and magnifiers are both assistive tools for people with visual disabilities, but they work with content in very different ways. A page can work well with magnifiers but still not work with screen readers if it lacks the right structure.
Assistive technology for hearing disabilities makes sounds louder, adds extra help or takes the place of audio information using devices that make sounds louder, visual signals and written forms of spoken communication.
In the real world, assistive technology for hearing problems includes hearing loops, visual alert systems and live captioning services.
Example
A theatre with an audio induction loop sends sound straight to a hearing aid or cochlear implant set to the T-coil mode. This cuts out background noise and helps the person hear the performance clearly.
Key point
Hearing loops only help people who wear hearing devices that work with them. They do not help people who are deaf and do not use hearing aids. Those people need visual or touch-based solutions instead.
In the ICT environment, assistive technology for hearing disabilities includes captions, transcripts, sign language in videos and visual or touch-based alert systems.
Example
A deaf person watching a video call uses live captions made by automatic speech recognition or a live captioner. Without captions, they cannot understand any spoken words no matter how good the video is.
Key point
Automatic captions often make many mistakes, especially with accents, technical words, and bad audio quality. They can help as a first step but are not as reliable as captions checked by a person.
Assistive technology for Deafblindness sends information through touch. This helps people move around and use digital content because they cannot rely on seeing or hearing.
In the real world, assistive technology for Deafblind people includes touch-based communication systems and helpers who share information about the surroundings through direct contact.
Example
A Deafblind person who uses hand-over-hand signing has a support worker sign directly into their palm. This touch-based sign language shares spoken communication in a way that neither seeing nor hearing can access.
Key point
Many Deafblind people depend on special helpers called intervenors. These helpers are trained to connect them to the physical world. This reliance on others is a big fairness problem when help is not available.
In the world of technology, assistive technology for people who are Deafblind is mostly the refreshable braille display. This device shows screen reader information as braille characters you can feel, and these characters change as the content changes. In the world of technology, assistive technology for people who are Deafblind is mostly the refreshable braille display. This device shows screen reader information as braille characters you can feel, and these characters change as the content changes.
Example
A Deafblind person reads a web page by moving their fingers over a special braille display that changes. This display shows one line of braille at a time and updates as they move through the page with a screen reader.
Key point
Refreshable braille displays cost a lot and only work with text. They cannot show pictures, so any content that is only visual, like charts or infographics, must have clear text descriptions to be accessible.
Assistive technology for mobility and body function disabilities helps people move or supports their movement. This includes mobility aids for moving around and special computer tools that let people use devices without needing precise hand or body control.
In the real world, assistive technology for mobility disabilities includes wheelchairs, walkers, artificial limbs and powered devices that help or replace a person’s own movement.
Example
A person with a spinal cord injury uses a powered wheelchair to move around buildings on their own. But the wheelchair only works well if the building has ramps, wide doors and lifts that are easy to to use.
Key point
Mobility assistive technology helps people move, but only as much as the surroundings allow. For example, a powered wheelchair cannot be used to go up stairs. Assistive technology and accessible design must work together; one alone is not enough.
In the ICT environment, assistive technology for mobility disabilities includes different keyboards, switch devices, eye-tracking systems, voice recognition software and mouth or head sticks.
Example
A person with quadriplegia uses an eye-tracking system to move a computer cursor by looking at things on the screen. Each part of the screen they need to select must be big enough and far apart so their eyes can easily target it.
Key point
Voice recognition is a tool for people with mobility disabilities, just like it is a handy feature for everyone else. People who need it because they have no choice are more affected when microphone access is blocked or voice control does not work well.
Assistive technology for thinking disabilities helps with memory, understanding organising, and finishing tasks. These tools help people do more by making up for differences in how their brains work.
In the real world, assistive technology for people with thinking problems includes visual schedules, reminder systems, guides for finding places and simple signs that make it easier to handle daily tasks.
Example
A person with an intellectual disability who uses public transportation depends on clear maps that show each stop and spoken stop announcements. Signs with only text or complicated directions make it hard to use, even when the bus or train itself is easy to access.
Key point
People often focus on physical and sensory access when designing spaces, but for people with intellectual disabilities, a building that is easy to move around in can still be hard to understand.
In the ICT environment, assistive technology for cognitive disabilities includes tools that read text aloud, help with reading, check spelling, suggest words and reduce distractions.
Example
A student with dyslexia uses a text-to-speech app to hear web page words read aloud while looking at them. They also use word prediction software to help with spelling when they write, so they can communicate more easily.
Key point
Cognitive assistive technology is the least standardised and most varied group. Unlike screen readers, there is no one main tool. Many people who use cognitive assistive technology depend on a mix of built-in operating system features, browser extensions and special applications.
Assistive technology for seizure disabilities helps stop seizure triggers and keeps people safe. In ICT settings, this means using tools and settings that block harmful visual content before the user sees it.
In the real world, assistive technology for seizure disabilities includes devices that alert others to seizures, protective helmets and medical ID tags that help keep people safe during and after a seizure.
Example
A person with epilepsy wears a medical alert bracelet so that first responders know not to hold them down during a tonic-clonic seizure. This simple device can be very important in an emergency.
In the ICT environment, assistive technology for seizure disabilities includes browser add-ons and system settings that find and block flashing or fast changing images before they appear.
Example
A browser add-on for people sensitive to flashing lights can automatically stop animated GIFs and mark pages with fast flashing content, lowering the chance of harm when creators have not used accessible design.
Key point
AT cannot completely make up for content that is hard to access here. A seizure might happen before the user can use a safety tool. Designing content to be accessible without expecting the user to protect themselves is very important.
Assistive technology for psychological disabilities helps people focus, lowers anxiety and makes tasks easier to handle. These tools often work like cognitive assistive technology and help control mental effort and emotions when using digital devices.
In the real world, assistive technology for mental health issues includes tools for the senses planned routines, and changes to the environment that lower stress and help people stay calm.
Example
A person with severe anxiety uses noise-cancelling headphones and a clear task list when working in a shared office. This helps reduce sudden noises and confusing thoughts, which lowers stress and makes it easier to finish tasks.
In the ICT environment, AT for psychological disabilities includes focus mode tools, content blocking extensions and apps that reduce mental and emotional overload — like hiding notification counts or limiting distracting content.
Example
A person with PTSD uses a browser extension that blurs or hides upsetting images before they show up. This lets them control what they see instead of having to avoid the web completely.
Key point
Assistive technology for psychological disabilities depends the most on a person’s ability to plan and set up their environment ahead of time. This can be a big problem for people who are having a sudden episode and cannot do these setup tasks.
Understanding of the data trends and implications of disability demographics and statistics.
Disability affects a large part of people around the world. The World Health Organization says that more than one billion people have some kind of disability, which makes them the biggest minority group in the world. Disability rates go up as people get older, are higher in poorer areas, and depend on how disability is defined and measured in each place.
Applying disability etiquette in practice.
Disability etiquette means following respectful rules when you talk or act with people who have disabilities. It means seeing them as whole people first, asking before you help and doing what the person with a disability wants.
Key point
Etiquette changes as community likes change and is not the same in all disability groups. What one group thinks is polite words or actions may not be liked by another group, and people in the same group also have different preferences.
Accessibility and Universal Design.
A personalised accommodation solves a problem for one person after the main design is made. Universal design includes access for as many people as possible from the beginning, so fewer people need special plans.
Key point
Universal design and accommodations work well together. Even a well-planned space might still need some special changes for certain people. Universal design makes these changes less often needed, but it does not get rid of the need completely.
Accessibility helps people with disabilities join in education, work and social activities. The benefits go even further: families, groups and all of society gain from the increased independence, new ideas and more chances to take part in the economy that inclusion allows.
Key point
The benefits are not just social. Leaving out people with disabilities from jobs causes clear losses to the country’s total economic output. This means that inaccessibility has a big cost for the whole economy, not just for individuals.
Web accessibility means websites, tools, and technology are made so that people with disabilities can use them. The W3C’s Web Content Accessibility Guidelines (WCAG) break this goal into four parts: content must be perceivable, operable, understandable, and robust.
Users must be able to get information using at least one of their senses. Content that is only in one form, just images or just sound, cannot be seen or heard by some users.
Key point
Perceivable means the user can receive the content, not just that the content is there. A video with audio description can be understood by blind users; the same video without it cannot.
Any content that is not text must have a text alternative that has the same purpose.
Example
A photo of a product on a shopping website needs alt text that explains what the picture shows, not just a file name like “img0042.jpg,” so people using screen readers get the same information as people who can see.
Audio and video need other options so people who cannot hear or see them can get the same information.
Example
A recorded lecture needs captions for deaf users and an audio description for blind users who cannot see what is happening on the screen.
The meaning must stay the same even when the way it is shown changes.
Example
A table that looks neat on the screen can sound like a mix of random words when a screen reader reads it aloud. That happens because the code does not reflect the way it looks.
Key point
“Presentation” is not just about what you see. It includes any way content is shown, like audio, braille, and adjusting to small screens.
Content should be easy to see apart from the background and other items around it. This can be done by using tools like colour contrast and allowing text to be resized.
Example
Light grey text on a white background may look neat to a designer, but it is hard for people with low vision or colour blindness to see the words clearly.
Key point
Colour should never be the only way to show information. For example, using just red and green to show pass and fail can be confusing for people who cannot see red and green clearly.
Users must be able to use and move around the interface, no matter what input method they use.
Key point
Operable means people can control technology in many ways, such as using a keyboard, switch, voice, eye tracking, and more. Designing only for mouse users leaves out many people who have trouble moving their hands.
All features must work using only a keyboard because many people with movement disabilities cannot use a mouse.
Example
A user who controls their computer with one switch moves through page parts using the Tab key. If a dropdown menu opens only when the mouse moves over it, that user cannot use it at all.
Users should be able to finish tasks without feeling rushed or being stopped unexpectedly.
Example
A banking website that logs users out after two minutes of not doing anything might be okay for someone who types fast. But a user with a motor disability who types slowly might have their session end before they finish filling out a form.
Content must not have flashing lights or movement that could cause seizures or make people feel uncomfortable.
Example
A flashing animated ad can cause a seizure in someone with photosensitive epilepsy, even if they did not choose to see the animation.
Users need ways to find content, understand where they are, and move through pages easily.
Example
A user who uses a keyboard moves with skip links to go past the main menu and reach the page content directly, saving many tab presses on each page they visit.
The function must work with many types of input, not just keyboards, but also touchscreens and pointer devices.
Example
A mobile screen that needs a hard swipe to work leaves out users who can only tap, like someone with a hand tremor who can use just one finger.
Key point
Input Modalities was added in WCAG 2.1 to cover mobile and touch devices that the original rules did not fully include. It works together with Keyboard Accessible and does not replace it.
Users need to understand both the content and how the interface works.
Key point
Understandable is the most human of the four principles. It means thinking about how people think, how they use language, and what they expect, not just about technical details.
The text must be easy to read and understand. You should also say what language the page is in so that assistive tools can pronounce words correctly.
Example
A screen reader set to English will say French words wrong unless the HTML says the passage is in French. This makes the user hear confusing audio that does not show what the text means.
Pages and parts must work in ways that users expect, without sudden or confusing changes.
Example
If picking an option from a dropdown menu automatically sends a form and opens a new page, a user who is looking through choices by pressing arrow keys might cause something to happen by mistake and cannot easily fix it.
When users make mistakes in forms, the interface should help them find and fix those mistakes.
Example
A checkout form that only makes a wrong field border red does not tell a screen reader user what is wrong or how to fix it. A clear error message in words, connected to the right field, helps all users.
Content must be made so that current and future devices, including tools that help people with disabilities, can understand it easily.
Example
A special interactive widget that looks visual but does not use usual HTML roles or ARIA labels will be invisible to a screen reader, because the assistive tool cannot understand what the widget is or how to use it.
Key point
Robust is focused on both the future and the present. Content made using web standards is more likely to work with assistive technologies that may be created in the future, not just with those available now.
Physical places like buildings, public areas and transportation must be designed so that people with disabilities can enter, move around and use them safely and on their own.
The universal design principles apply here as they were first created for buildings and spaces.
Example
Building codes and regulations set a legal minimum. They define what is required, not what is ideal. Universal design goes further by aiming for spaces that work well for everyone, not just spaces that meet the lowest threshold the law requires.
Universal design creates places and things that work for as many people as possible, no matter their age, size or ability, without needing special changes. The seven principles below give designers a clear list to follow to achieve this.
Key point
Universal design is often mixed up with accessible design. Accessible design focuses on people with disabilities. Universal design is made for everyone. When we design well for all kinds of people, it naturally helps people with disabilities too.
The design must be helpful and attractive to people with many different abilities. It should give everyone the same way to use it when possible, and a similar way when the same use is not possible.
Example
A building entrance that has only steps in front makes wheelchair users use a different side entrance. A ramp at the front that everyone can use is fair; a hidden ramp at the back is not.
Key point
Equitable use means that the design does not treat any group unfairly or separate them from others. A separate “accessible entrance” at the back of a building might follow the basic rules but breaks this idea because it separates and leaves out some users.
The design fits many different people’s likes and skills. It lets users pick how they want to use it and works at their own speed.
Example
Scissors made to work with either the left or right hand, and that can be used at different speeds, help many more people than regular right-handed scissors.
The design is simple to understand no matter what the user’s experience, knowledge, language skills or focus level is.
Example
A washing machine with one dial that shows wash cycles using easy icons is good for new users, older people or those reading in a second language, because it does not need technical skills or language fluency.
The design shares important information with the user in different ways, such as pictures, words and touch, so it works for people with different senses.
Example
A crosswalk with a sound and a textured strip on the ground sends the same “safe to cross” message to people who cannot see the green light and to people who cannot hear the sound.
Key point
Perceptible information is about repeated details in different senses, not just saying the same thing again. Each format shares the same important meaning, so no single type stops any user from understanding.
The design reduces dangers and the harmful effects of accidental or unintended actions.
Example
A power saw that needs the user to press two buttons at the same time before the blade turns on stops accidental starts and keeps safe users who may have trouble with hand movements or slower reactions.
Key point
Accepting some mistakes is not the same as stopping all mistakes. The principle says that mistakes should not cause serious harm. This is done by using warnings, safety features and designs that stop people from making accidental errors during important tasks.
The design is easy to use and causes little tiredness. It keeps the body in a natural position and lowers the need for repeated or long lasting effort.
Example
A lever door handle that opens with a light push down needs much less grip strength and wrist effort than a round knob. This makes it easier to use for people with arthritis, weak hands or full hands.
The design gives enough size and space for reaching, moving and using it, no matter the user’s body size, posture or mobility.
Example
A ticket machine with a screen that both standing and sitting users can see, and enough space on the floor for a wheelchair to come next to it, is useful for many more people than a machine made just for a standing adult of average height.
Key point
This principle clearly allows the use of assistive devices. A space that a wheelchair or walking frame can reach but does not leave enough room to move around does not follow the purpose of the rule.
UDL uses universal design principles in teaching and learning. It is a way to create lessons that help learners with different needs, likes, and abilities right from the beginning, instead of changing lessons later.
Key point
UDL is a way for teachers to plan lessons, not just a list of special help for students with disabilities. It asks teachers to plan for all students to have flexible learning from the start, instead of fixing problems as they come up.
The UDL framework is based on three main principles. Providing multiple means of:
Teachers need to give many ways to motivate students and keep them trying because students are different in what interests them and helps them stay focused and in control.
Example
One student does well with creative tasks that have no set rules, while another student feels stressed by these tasks and needs clear instructions and a routine. A teacher who gives both choices helps each student find a way to learn the material.
Key point
Engagement is not only about making learning “fun.” It includes helping learners set goals, sustain effort over time and manage their own emotional responses to challenge. These will all vary across individuals and contexts.
Teachers need to share information in more than one way because students understand and learn in different ways based on their senses, language and learning preferences.
Example
A science idea explained only in a hard to read text might be clear to a good reader but hard to understand for a student with dyslexia. Using a labelled picture and a short spoken explanation helps all learners understand the text.
Key point
Representation is not about making content simpler. It means giving many ways to access the same content, so the way it is delivered does not stop people from understanding.
Teachers need to give students more than one way to show what they know, because people are different in how they can use materials and how they best show what they understand.
Example
A student with cerebral palsy might not be able to finish a written test in the time given, but they can show what they know by giving a recorded spoken answer. Giving both choices stops the format from getting in the way of showing skill.
Usability shows how easy it is for someone to use a product to reach their goal. User experience (UX) is wider. It includes every part of the interaction; from the first time someone learns about it to feeling trust and being happy with it over time.
Example
A website can work technically. For example, a person using a screen reader can move around it and send in a form. But the experience is bad if error messages are confusing, the layout is messy and the process feels unfriendly. Accessibility is needed for a good user experience, but it is not enough by itself.
Key point
Usability and accessibility are connected, but they are not the same. A product can work well for most people but still be hard to use for people with disabilities. Good UX design must treat accessibility as a necessity, not just an extra feature.
Standards, laws and management strategies.
Identifying and describing global agreements about the rights of people with disabilities.
International agreements set the worldwide standard for human rights, including the rights of people with disabilities. They include declarations, which set rules and expectations, and conventions, which are legally binding for the countries that agree to them.
The Universal Declaration of Human Rights (1948) was the first document to explain basic rights that belong to all people everywhere. It is the base that later tools for specific disabilities are built on.
Key point
The UDHR does not name disability as a protected characteristic. People with disabilities are included in its general human rights rules, but not mentioning them clearly left a gap that later agreements, especially the CRPD, were made to fix.
The CRPD (2006) is the first international treaty that legally protects the rights of people with disabilities. It changes the focus from charity and medical care to rights, independence and being fully involved in society.
Key point
Signing and agreeing to the CRPD are two different things. A state that signs shows its intent; a state that ratifies accepts legal duties. Countries that have agreed must take real action to make the rights happen, not just accept them.
The Marrakesh Treaty (2013) is a law that lets people with print disabilities, like blindness and dyslexia, make and share easy to read copies of books and other works without asking the owner for permission.
Key point
The Marrakesh Treaty is where copyright law and accessibility come together. Without it, changing a book into braille or audio could break copyright rules. The Treaty takes away that legal barrier just for people with print disabilities.
Identifying and characterising regional instruments on human and disability rights.
Regional agreements turn international human rights ideas into rules that match the laws, cultures and needs of different areas of the world. They can make protections stronger than global treaties require, and they let people use regional courts and enforcement systems.
The Charter of Fundamental Rights of the European Union (made in 2000 and legally binding from 2009) brings together the basic rights of all people living in the EU. It clearly bans discrimination against people with disabilities and supports their right to be independent and take part in society.
Key point
The EU Charter is built on top of an older set of European rights laws. The European Convention on Human Rights (1950), binding on all Council of Europe members, also covers disability, but only indirectly under “other status” — disability is not named. The Charter is clearer and to the point.
Disability is not named in its anti-discrimination provisions, but the Charter has been used to challenge disability discrimination. The African Disability Rights Protocol (2018) adds specific disability protections as a supplement to the Charter. The Charter is clearer and to the point. Disability is not named in its anti-discrimination provisions, but the Charter has been used to challenge disability discrimination. The African Disability Rights Protocol (2018) adds specific disability protections as a supplement to the Charter.
Key point
As of 2023, the African Disability Rights Protocol still needed 15 more countries to agree to it before it could start working. It exists and has been accepted, but it is not yet required by law for member states.
The Inter-American Convention on the Elimination of All Forms of Discrimination Against Persons with Disabilities (1999) was the first regional treaty that clearly and directly banned discrimination against people with disabilities. It asks member states to take clear actions to remove obstacles and support full social integration.
Key point
The Inter-American Convention was created seven years before the CRPD, making it one of the first important laws to protect disability rights. But it covers less than the CRPD. It aims to stop discrimination and remove barriers, while the CRPD uses a wider human rights approach.
Identifying and characterising national and provincial instruments on human and disability rights.
National and provincial laws turn international duties into rights that can be enforced within each country. They explain what people with disabilities have the right to, what organisations must do and what happens if the law is broken.
The UK Equality Act 2010 combined several older anti-discrimination laws into one set of rules. It stops unfair treatment based on a list of protected traits, including disability, and covers both direct and indirect unfair treatment, as well as unfair treatment because of a disability.
Key point
The Equality Act distinguishes between direct discrimination, which means treating someone worse because they have a disability; indirect discrimination, which is when a rule that seems fair actually makes things harder for disabled people; and discrimination arising from disability, which means treating someone badly because of something related to their disability. These are three separate legal tests, not just one.
The ADA is a civil rights law that protects people with disabilities from being treated unfairly in jobs, public places, transportation, phone services and state and local government programs. It treats discrimination against people with disabilities the same as discrimination based on race, sex or religion.
Key point
The ADA does not have clear technical rules for digital accessibility. Federal websites are protected by a different law called Section 508. Private business websites are protected by the ADA’s public accommodations rules, but most enforcement has come from lawsuits instead of set technical rules.
The Ontarians with Disabilities Act of 2001 promises that the Government of Ontario and all parts of Ontario will work to find and remove barriers for people with disabilities and make sure these barriers do not come back.
Key point
The AODA mainly focused on public services and was seen as having limited impact. In 2005, the AODA was passed. It included more rules for private businesses and created clear, enforceable accessibility standards. In 2005, the AODA became law. It added rules for private companies and made clear, enforceable accessibility standards.
All EU member countries follow the EU Employment Equality Directive, which stops disability discrimination in jobs. Beyond jobs, member states differ a lot. Some ban disability discrimination in many ways, some make sure people get fair help, some do both and some do neither.
Key point
The EU has not yet finished making disability discrimination laws the same in all countries. Job protections are the same in all member states because of the directive. But protections outside of jobs, in health care, schools, and housing, are very different in each country.
Identifying and characterising domain-specific and government procurement laws and regulations.
Some accessibility laws focus on certain areas or activities instead of setting wide rules against discrimination. These laws explain clearly what accessibility means for things like transportation, communication and government buying.
Laws for specific areas make sure accessibility rules are followed in certain fields. They might be made just for accessibility, or they might be bigger laws where accessibility is very important. Examples include laws about air travel, TV and radio broadcasting and digital communications.
Key point
Laws for specific areas work together with general anti-discrimination laws; they do not replace them. A company might follow a law for its specific industry but still get claims of discrimination under a wider law. The opposite can also happen.
Laws say that government agencies must buy ICT products and services that are easy for everyone to use. By requiring accessibility in government contracts, these laws create pressure that affects what vendors make, even outside the public sector.
Key point
Procurement law is one of the strongest tools for making things accessible on a large scale. When a big public agency asks for accessibility in all ICT purchases, suppliers must follow those rules to try to get contracts. This often means making their products better for all customers, not just government ones.
Applying accessibility standards and regulations to ICT.
ICT accessibility standards explain the technical rules that digital products and services must follow. Laws in this area usually work by pointing to a set technical rule and following this rule is how you follow the law.
In the US, Section 508 of the Rehabilitation Act says that federal agencies must make their technology easy to use for workers and people with disabilities. Federal agencies must follow the Section 508 Standards, which use WCAG for web content. The ADA protects private websites by calling them public places and is enforced through lawsuits.
Key point
Section 508 and the ADA are two different laws that cover different areas. Section 508 applies to federal agencies and sets clear technical rules. The ADA covers more situations but does not set exact technical rules. Courts have said it requires accessibility, but the specific standard of “what counts” is decided in each case.
In the EU, public websites and apps must follow rules to be easy for everyone to use. The European Accessibility Act sets rules for important products and services in private companies. Both instruments refer to EN 301 549, the European standard that includes WCAG.
Key point
The Web Accessibility Directive and the European Accessibility Act cover different areas. The Directive applies to public sector organisations. The Act covers private sector products and services in certain areas like banking, online shopping, transport and more. Neither of them covers everything. There are gaps, especially for internal government tools and small businesses.
To make accessibility last, you need more than just knowing the rules. Organisations need to include accessibility in their culture, processes, buying decisions and hiring so it becomes an ongoing program, not just a one-time project.
The W3C Web Accessibility Initiative gives organisations a clear plan to help them start, organise, carry out and keep an accessibility program going. The framework starts by creating internal awareness and a business case before moving on to implementation.
Key point
The WAI framework sees accessibility as a change in how organisations work, not just as technical tasks. A group that only fixes code but does not get leaders’ support, teach staff and set clear goals will probably not keep making progress.
These guidelines help organisations share information so everyone can understand it, including people with disabilities. They include four steps: policy, plan, practice and review. They stress that making information accessible should be part of regular work, not a separate job.
Key point
The guidelines apply to all the information an organisation makes, not only its website. Internal documents, publications, videos and buying rules are all included. Many organisations miss this gap when they only focus on their public digital content.
Accessibility maturity models help organisations see where they stand and follow their progress over time. They usually describe a range from unplanned and random at the low end to constant improvement and new ideas at the top.
Key point
No one maturity model is the official standard. The W3C, the Business Disability Forum and Carnegie Mellon’s version of the Capability Maturity Model all provide different frameworks. The right model depends on an organisation's context. What matters is using one consistently rather than which one is chosen.
Accessibility champions are people chosen in different parts of an organisation to support accessibility in their teams. They help build skills and awareness, and keep things moving between official accessibility reviews. When no one inside supports accessibility, the work often stops when outside pressure goes away.
Key point
A management champion is different from a technical lead or an accessibility specialist. Champions come from all parts of the organisation. From HR, legal, marketing and product. Their job is to include accessibility ideas in decisions at every level, not to do accessibility checks themselves.
Accessibility checks should be done early and often throughout the design and development process. Finding and fixing problems before a product is released is much cheaper and easier than adding accessibility later.
Key point
Automated tools can find only some accessibility problems. Estimates vary, but these tools usually catch about 30 to 40 percent of the issues. Human testing, including with people who use assistive technology, is very important and cannot be replaced by tools alone.
To create an accessible organisation, you need to hire people with disabilities, and hire staff who have digital accessibility skills. Both goals rely on easy-to-use hiring steps. If the job application system is hard to use, then both goals will fail from the beginning.
Key point
Hiring people for disability inclusion and hiring accessibility specialists are connected but different tasks. An organisation can do both, but mixing them up can make people with disabilities seem like only experts in accessibility instead of employees who contribute in all jobs.
All communications a company makes, internal and external, must be easy for everyone to use. This includes text and video, on the web and in print. This means creating rules, training people who share information, adding captions to videos and making sure all published documents are easy for everyone to use.
Products and services that are not accessible can cause legal problems in places where accessibility is required by law, and can hurt a company's reputation everywhere. Organisations must check their legal risks and have their accessibility statements reviewed by legal experts before publishing.
Key point
Accessibility brings both risks and chances for public relations. Poor accessibility can lead to bad attention and lawsuits, but good accessibility shows real care for inclusion. This can make a company stand out and connect with customers, workers and the public.
When a company buys products or hires services, they must clearly say that accessibility is required in the contract. Checking if vendors are truly accessible, instead of just believing their claims, is an important part of responsible buying.
Key point
Buying goods and services for the government is very powerful because it happens on a large scale. When government agencies ask for accessibility in big contracts, it affects supply chains and can improve basic accessibility in many markets, not just the public sector.