My notes for making the web more inclusive. Don't follow this guide blindly. Read the references to learn more about certain rules.
Check out my general best practices for building better applications.
This page is a continuous work in progress.
To evaluate the accessibility of a web page, try out the following tools:
- WCAG Quick Reference
- WAI-ARIA Authoring Practices 1.2
- A11y Reviews (GitHub)
- Accessibility interview questions
- IBM Accessibility Checklist 7.1
- Accessibility motivation
- Provide a correct lang attribute.
- Ensure that interactive controls have at least a 44x44 pixels target click size.
- Accessible, responsive canvas.
- a11y-dialog - Accessible JS modal dialog.
- Comica11y - accessible comics.
- Accessibility tools audit — An example page to test the effectiveness of accessibility tools.
- There are multiple issues with AccessiBe and other overlays.
- Building the most inaccessible site possible with a perfect Lighthouse score.
- The WebAIM Million - An annual accessibility analysis of the top 1,000,000 home pages.
- Losing sight.
- I'm a software engineer going blind, how should I prepare?.
- A blog where the author describes their way to become certified in WAS and CPACC.
- Don't disable outline, master it instead.
- It is not required that hover as a state is differentiated from the default (and presumably all other) states.
- Adjusting the flex order does not change the focus order.
- Provide a fallback for Windows High Contrast mode when using a
- A keyboard-only focus ring has pros and cons, but it is technically possible using
:focus-visible. Progressive enhancement handles older browsers.
- Alt-Texts — The Ultimate Guide.
- Add punctuation to your alt text.
- There are limitations of
aria-describedby. It's complicated.
- Google Translate does not translate
- HTML for vs wrapping label.
- There's no evidence that typefaces designed to help dyslexics have any effect.
- Accessible font types.
- Atkinson Hyperlegible Font.
- WCAG-compliant website showcase
- Rules for using ARIA.
- An in-depth guide to ARIA roles.
passwordrole is under discussion.
role="none"is not supported in IE11.
- Do not put
aria-hiddenon focusable elements.
- NVDA Keyboard Shortcuts
- User survey 2019 (browser/screen reader usage)
- Do not use screen reader detection.
- Screen reader icon (public domain):
- A screen reader may announce things differently than displayed in the text viewer. Pay attention to times, dates, currency, punctuation, special characters, emoji, math symbols, common (and uncommon) abbreviations & acronyms.
- Minus the minus - A PSA about screen readers and negative numbers.
- NVDA has fixed a related issue.
- Talkback doesn't recognize the
- Acronyms can usually be left as-is.
- NVDA announces values differently between divs and spans.
- NVDA does not announce emphasis elements (like
- Improve the announcement of phone numbers:
<a href="tel:703555121" aria-label="7 0 3. 5 5 5. 1 2 1.">(703) 555-121</a>
::aftercontent is screen reader accessible (except IE11).
- CSS generated content is not fully accessible.
- How the
- German gender characters are not excluding screen reader users.
- ☑ Tools → Speech viewer
- ☑ Show Speech Viewer on Startup
- ☑ Preferences → Keyboard → Select NVDA Modifier Keys → caps lock
- ☑ Tools → Speech viewer
- NVDA does not focus inline links in browse mode, unless the link appears at the start of a line.
- ☐ Verbosity → Hints → Speak instructions for using the item in the VoiceOver cursor
- ☑ Sound → Mute sound effects
- HTML: The Inaccessible Parts.
- Avoid strikethrough element, as the semantics are not announced by screen readers.
Something I see (...) is the frustration with date fields that are anything other than a plain text field for well-known dates (like birthdays).
<dd>Black hot drink</dd>
<dd>White cold drink</dd>
It's worth noting that a definition list is the correct way to mark up a list of paired items. Changing markup patterns to satisfy the vagaries of specific assistive technologies tends to be a slippery slope. (source)
- There is no fixed rule where the focus should be moved to after opening a modal. A headline or the dialog itself are two good possibilities. There is an ongoing discussion about the default behavior for the HTML
legendhas to be a direct child of a
fieldset. A screen reader might not announce the label if the markup is malformed (e.g. NVDA). Solutions:
- Use a duplicate label
- There was a Chrome bug, making it impossible to adjust the
There are some rules regarding the
- The HTML footer element defines a
contentinfolandmark when its context is the body element.
- The HTML footer element is not considered a contentinfo landmark when it is descendant of any of following elements:
- Use a single H1 per page. It doesn't have to come first, though (example).
- Don't skip headline levels, even though it's not a WCAG violation.
- Decorational images:
We tried to outsmart screen readers by letting them skip descriptive images. This turned out to be really unhelpful. Users that are not fully blind will still see an image and when the screen reader skips these images, users will assume they missed out on information. Solution: let the screen reader tell the users it’s a descriptive image. Or even better, write a descriptive alt-text for images. source
- Background images are mostly ignored in Windows High Contrast mode.
type="search"for search inputs, even though it currently offers little benefit.
<span id="new-window-0">Opens in a new window</span>
<span id="new-window-1">Opens an external site</span>
<span id="new-window-2">Opens an external site in a new window</span>
- Download links:
<a>, not a
- Provide media type and file size visually readable.
- The trouble with mailto email links and what to do instead.
<path d="..." />
- Include a table caption:
<caption>Populations of cities</caption>