Screen readers and assistive technologies: Using a computer without a screen

In short: Screen readers read the screen content aloud or output it in Braille; other aids support people with visual, hearing, motor or learning impairments.

In more detail: Millions of people use computers and smartphones with special aids called assistive technologies. For web development and everyday life it is worth knowing how they work, because only well-built pages can be used with them.

In Depth

Screen readers

A screen reader reads text, buttons, headings and image descriptions aloud (speech output) or outputs them on a Braille display. It is operated with the keyboard: with keys you jump from heading to heading, link to link or form field to form field. Well-known programs: NVDA (free, Windows), JAWS (paid, Windows), VoiceOver (macOS, iOS), TalkBack (Android), Orca (Linux). The screen reader does not use image information but the document’s structure (accessibility tree).

Other aids

• Screen magnifier and high contrast, large type for low vision.
• Speech recognition for control (voice commands) and dictation.
• Alternative input devices: trackball, head or eye control, one-handed keyboards, switch systems.
• Subtitles and sign language for deaf people.
• Read-aloud functions, reading aids and plain language for dyslexia or cognitive impairments.

What websites need for this

Semantic HTML (headings h1 to h6, lists, tables with headers, button instead of clickable text fields), alternative text for images (alt), labelled form fields (label), visible keyboard focus, sufficient contrast, and ARIA only where HTML is not enough. The WCAG guidelines and the Accessibility Strengthening Act (BFSG) make this mandatory for many offerings.

Try it yourself

Switch off mouse and screen for a while: start NVDA or VoiceOver (Cmd+F5) and navigate your site only with the keyboard. Tab order, labels and hints quickly reveal gaps. Automatic checkers such as Lighthouse or axe find part of the problems but do not replace testing with people.

See also: Building accessible websites, WCAG and colour contrast, BFSG, Semantic HTML