Assistive technology is hardware or software that gives a person with a disability more than a mainstream browser offers on its own. It either acts as the browser itself or works alongside one, and WCAG names four things it does. It presents content another way. Speech, or magnified text. It accepts another kind of input, like voice. It adds ways to navigate, which is what a screen reader's headings list really is. And it transforms content, which covers the reading and simplification tools people with cognitive disabilities rely on. Your site never talks to it directly. The browser builds a description of your page, the operating system passes that on, and the tool reads what arrives.
In practice
The category runs wider than screen readers. Magnifiers, braille displays, switch devices, voice control and eye tracking all sit inside it. So do the browser extensions people with cognitive and learning disabilities use to reformat pages, simplify text, mask distractions and read aloud. That last group is the one most lists leave out, and W3C's instruction to authors about it is one line long. Do not disable add-ons and extensions.
Free tools are widely used and the market leader is still paid. NVDA is a free download and is the most commonly used screen reader, at 65.6% of survey respondents against JAWS at 60.5%. JAWS is still the most common primary one at 40.5%, though, and where your readers live changes the answer completely. JAWS leads in North America by better than two to one. NVDA leads in Europe, Africa, the Middle East and Asia, and in Asia by more than three to one. Single-line braille displays were running $3,500 to $15,000 in 2026, which is where the it-is-all-free-now story ends.
The line between assistive technology and an ordinary browser feature is not sharp, and W3C says so itself. The test it offers is who the software was built for. Mainstream tools target broad audiences that include disabled and non-disabled people. Assistive technology targets narrowly defined groups with specific disabilities. Browser zoom sits on the mainstream side of that line, which is why the resize rule asks for text to scale without assistive technology at all.
Why it matters
Most assistive technology can only work with what your markup exposes. It is reading your page rather than repairing it, so everything WCAG asks for comes down to giving these tools something true to work from. The reading and simplification tools are the partial exception, since transforming content is the whole point of them, though even they are working from the structure you gave them. Testing with them is also the cheapest thing on your list. VoiceOver ships with every Mac and iPhone, TalkBack with Android, Narrator with Windows, and NVDA is a free download, so the first honest test of your site costs an afternoon rather than a budget. Just do not test with one and call it finished. Nearly a third of VoiceOver users run a different screen reader at work than they do at home.
What actually reaches them
The browser builds an accessibility tree from your page. The operating system exposes that tree through its own accessibility interface. A screen reader reads from there, and a braille display then takes its text from the screen reader rather than from the platform, so one fix in your markup reaches both. Switch software works the other way round and sends keystrokes in. A magnifier is the odd one out again, working largely from the pixels on screen rather than from the tree.
Where this shows up on the site
Related terms
- Screen readerA screen reader is software that reads the screen out loud, or sends it to a braille display, for people who cannot see it.
- Braille displayA braille display is a hardware device with cells whose pins rise and fall to form braille characters, refreshing as the reader moves through a page.
- Switch deviceA switch device is an input for people with severely limited movement, and the picture most people have is a single large button pressed with a hand, head or knee.
- Voice controlVoice control means operating a computer by speaking, saying things like "click Submit" or "scroll down", and it is built into macOS, iOS, Windows and Android.
- Screen magnifierA screen magnifier enlarges part of the screen, from the zoom built into every operating system up to dedicated software like ZoomText.
- User agentA user agent is any software that retrieves and presents web content, which takes in browsers, media players, plug-ins, and assistive technology as well.
Knowing the word is the easy part.
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