Accessibility

Conformance target

We aim for this website and the Sandbox to conform to the Web Content Accessibility Guidelines (WCAG) 2.2 at level AAA, in English, Spanish and Chinese, in the light and the dark theme. Every page is checked with automated tests (axe-core plus our own checks for the AAA criteria) and walked through with the keyboard.

Reading preferences

The site sets its prose justified and hyphenated, like the books Postext makes. If you find that harder to read, the book icon in the menu bar opens the reading preferences. They apply to every page of the site and are kept in this browser.

• Theme: light or dark. It is the same setting as the switch in the menu bar; with no choice made, the site follows your system.
• Text alignment: justified as designed, or left-aligned with no hyphenation.
• Line spacing: as designed, or 1.8 lines with paragraph gaps one and a half times the line spacing.
• Line length: as designed, or 80 characters at most (40 in Chinese), with two-column text set in one column.
• Colours: the theme's own, high contrast (black on white, or white on black in the dark theme) or warm paper.
• Text can be enlarged to 200% with the browser's zoom and pages still fit the window without scrolling sideways.

You can also set them in the panel on this page.

In the Sandbox, buttons and fields are compact by default so the editor can show more at once. The hand icon at the bottom of its left bar (at the top on a phone) turns on large buttons and fields, every one at least 44 × 44 pixels. It starts on with a touch screen and is kept in this browser.

Keyboard use

• Tab and Shift+Tab move between links and controls, and an outline shows where you are.
• The first Tab stop on every page is a link that skips to the main content.
• Enter or Space activates buttons; the arrow keys move between the choices of a group.
• Esc closes menus, the search window and the reading preferences, and returns focus to the button that opened them.
• Ctrl+K (⌘K on a Mac) opens the documentation search.

Known limitations

These parts of the site do not meet the target yet:

• The two narrated videos have no sign-language interpretation (WCAG 1.2.6) and no extended audio description (1.2.7). Each video has a full transcript under the player that describes what happens on screen as well as the narration.
• The video caption tracks hold speech only and are labelled as subtitles; sound and music cues are not yet captioned.
• There is no Chinese cut of the videos: Chinese pages play the English video with a Chinese transcript.
• The page preview in the Sandbox's Canvas tab is a picture of each page. Its text is in the HTML tab and in the Text panel, where screen readers can read it.
• Books you export as PDF from the Sandbox are tagged for accessibility, but how readable they are depends on the content and design you give them.

Report a problem

If something on the site is hard or impossible to use, please open an issue on GitHub (opens in a new tab). Tell us the page, what you were trying to do, and the browser and assistive technology you use.