Screen readers, browser plug-ins, color contrast analyzers, and other tools for the viewing or creation of websites and digital applications.
Screen Readers and Assistive Technology
Assistive technology (AT) is the general term for tools that people with disabilities use to access the Web. Screen readers are the most common type of AT.
NVDA – best with Firefox. NVDA (NonVisual Desktop Access) is a free, open source screen reader.
- The NVDA keyboard commands.
- Advice on testing while using NVDA.
- An add-on for NVDA that highlights the words being spoken.
- Instructions for obtaining and setting up NVDA on Macs. (TBD)
VoiceOver (iOS) and Talkback (Android) are built in to their respective operating systems.
- VoiceOver can be used with the sound off and just the captions, which is helpful. (However, the captions do not always fully reflect what a word will sound like when spoken by the screen reader — for example, words in ALL CAPS or abbreviations.)
- An article with helpful info on how to use VoiceOver.
- A video covering the basics of using VoiceOver (YouTube).
JAWS for Windows Screen Reader desktop software – best with Internet Explorer.
- You can download a trial version and use it for 40 minutes at a time. (The professional version costs $1,100 but despite its high cost, JAWS is still the #1 screen reader by market share.)
- JAWS HTML Support is a chart that explains where JAWS fully, partially, or does not support the various HTML elements.
- JAWS ARIA Role Support is a chart that explains where JAWS fully, partially, or does not support the various ARIA roles. Both of these charts are useful to check after JAWS refuses to read something the way you think it should. It may be that JAWS simply doesn’t support the HTML element or ARIA role you’re using. (These would be considered deficiencies in the JAWS software, and not WCAG failures.)
Deque Systems, an accessibility consulting firm, put together a presentation and support materials showing the use of screen readers.
- Intro to Screen Readers (YouTube video, 57 minutes 15 seconds) with Steve Sawczyn (2018, May).
- Intro to Screen Readers (PDF, 13 pages) (2018, May).
- Screen Reader survival guide – essential keyboard shortcuts for NVDA, JAWS, and VoiceOver.
Windows has a Magnifier built into it. From the Start button search, input ‘magnifier’. Or, you can find it in Control Panel, Ease of Access Center, Start Magnifier.
MAGic Screen Magnification desktop software. You can download a trial version and use it for 40 minutes at a time. Many users with visual impairments use a screen magnifier like this one.
ZoomText Magnifier is another screen magnification product.
Dragon NaturallySpeaking Professional is a top-of-the-line speech recognition software package. You would need to invest significant time to learn this tool.
Level Access created video demonstrations of Dragon in use and also a demonstration of Dragon being used to control Microsoft Word.
Most smartphones have built-in voice recognition.
Devices like the Amazon Echo and Google Home increase the spread of voice recognition.
Use the browser’s accessibility functions (e.g. text size, zoom, no page style) to determine whether or not the site responds as expected to those functions.
Simply trying to use your website with the keyboard (hide your mouse) can tell you a lot about the accessibility of the site.
These validators scan a webpage for proper code and markup, both of which make for better accessibility and better code quality in general.
- The W3C HTML Validator checks the markup validity of Web documents in HTML, XHTML, etc.
- The Nu HTML Checker is an experimental HTML validator. (I’ve never had any problems with it, but officially this is still a beta version.)
- WCAG parsing error bookmarklet filters the results of the Nu HTML Checker to show only the WCAG violations.
- HTML Validator add-on for Firefox verifies that web pages have correct syntax.
Do not be surprised if these validators report hundreds of errors on a typical webpage.
Single page and sitewide evaluation tools.
- WebAIM WAVE is one of the standard accessibility testing tools.
For evaluating Flash, AJAX, and other rich Internet applications.
Add-ons and Toolbars
They extend the capability of the browsers to help you easily find accessibility issues.
- WAVE toolbar
- Jim Thatcher’s Favelets
- Firebug add-on for Firefox
- Web Accessibility Toolbar (WAT) plug-in for Internet Explorer
- Web Developer Extension for Firefox
- Accessibility Inspector in Firefox Dev Tools
- aXe (Accessibility Engine) extension by Deque – a plug-in that lets you ‘audit’ a webpage for WCAG compliance. Similar to the WAVE toolbar.
- Juicy Studio Accessibility Toolbar add-on for Firefox
- HeadingsMap (Chrome) or HeadingsMap (Firefox) – shows you the HTML5 outline of a page as well as the Headings (H1, H2, … H6). Useful for checking if the hierarchy makes sense.
- tota11y bookmarklet – allows you to see Headings, Contrast, Link Text, Labels, Image Alt-Text, Landmarks. Similar to the WAVE toolbar.
- Visual ARIA bookmarklet – allows engineers, testers, educators, and students to physically observe ARIA usage within web technologies, including ARIA 1.1 structural, live region, and widget roles, proper nesting and focus management, plus requisite and optional supporting attributes to aid in development.
Color Contrast Analyzers
- Vischeck Colorblindness Simulator – PhotoShop plug-ins for Mac or Windows
- Color Oracle – color blindness simulator for Mac
- Google Accessibility Color Enhancer
- Google Accessibility High Contrast
- Color Contrast Analyzer 2.2 – a tool for checking foreground & background color combinations to determine if they provide good color visibility. It also contains functionality to create simulations of certain visual conditions such as color blindness.
- Luminosity Colour Contrast Ratio Analyser
- Contrast Rebellion
- Hex Naw – a tool that allows you to create a palette of colors and then tells you the level of color contrast of each color against every other color at both small and large text size.
- Contrast Finder is a tool which computes the contrast between two colors (background, foreground) and checks if the contrast is valid. When the contrast is not valid, the main target is to suggest some correct colors contrasts.
Useful Accessibility Tools presentation by Graham Armfield (on Slideshare).
Other Examples of Assistive Technology (AT)
Screen Readers (Text-to-Speech)
Voice Recognition (Speech-to-Text)
Proofing tools, Note-taking & Literacy Aids
Ergonomic Aids ad RSI (Repetitive Strain Injury)
Mind Mapping & Organisation Aids
OCR (Optical Character Recognition)
Software for creating and reading sound files (e.g. Daisy files) such as Easy Producer and Easy Reader
Software for creating Braille such as Duxbury
Mice & Pointing Devices
Headsets, Microphones & Recording Devices including Dictaphones
Braille Devices e.g. Braille Displays, Pacmates, and Embossers
Telephony and equipment to support hearing impaired users (e.g. in face to face meetings)
Magnifiers including CCTV systems
Ergonomic Support Equipment
Large monitors and monitor arms
Personal printers e.g. for visually impaired users, or users with limited mobility
Hardware specifically to enable a user to work from home or while out of the office. For example, laptops for users who would ordinarily have a desktop, 3G and / or broadband at home.