Accessibility (a11y)

The territory

28 core terms mapped for this field, ranked by how often builders reach for them. Each one is a future entry. Want to bust one? One entry, one file, one pull request.

• Alt textWritten description of an image read aloud by screen readers"the words a blind person hears instead of the picture" · "image caption for screen readers"
• Screen readerSoftware that speaks or brailles on-screen content for blind users"the voice that reads the page" · "blind people's software"
• Keyboard navigationOperating the whole interface with Tab, arrows, Enter, Escape"using it without a mouse" · "tabbing through everything"
• Focus ringVisible outline showing which element the keyboard is currently on"that blue glow when you tab" · "the box around the button"
• Color contrast ratioNumeric measure of text legibility against its background"is this gray too light" · "readability score for colors"
• Semantic HTMLUsing meaningful elements instead of generic divs and spans"using real buttons not divs" · "proper tags"
• aria-labelInvisible accessible name attached to an unlabeled control"name for the icon button" · "hidden label for the X button" · "ARIA label"
• Accessible nameThe string assistive tech announces for a control"what the screen reader calls it" · "the button's real name"
• Tab orderSequence in which Tab moves focus through interactive elements"the order things get selected" · "the tabbing path"
• Focus managementDeliberately moving focus after route changes or actions"sending focus to the right place" · "where the cursor goes after you click"
• Focus trapConfining keyboard focus inside a modal until it's dismissed"keeping tab stuck inside the popup" · "not tabbing behind the dialog"
• Modal dialog semanticsrole="dialog", aria-modal, return focus on close"making the popup accessible" · "proper markup for a dialog"
• ARIA live regionZone that announces dynamic updates without moving focus"make the screen reader say the toast" · "announce when it changes"
• Heading hierarchyOrdered H1-H6 outline screen readers use to navigate"the H1 H2 H3 structure" · "using headings in the right order"
• Landmark regionsHeader, nav, main, footer roles screen readers jump between"page sections a screen reader can skip to" · "structural areas"
• Skip linkHidden top link that jumps past nav straight to main content"jump to content thing" · "skip the menu shortcut"
• Form label associationBinding a label to its input so clicks and readers work"connecting the text to the box" · "label that belongs to the field"
• Visually hidden (sr-only)Text hidden on screen but still read by screen readers"invisible text for screen readers" · "off-screen label"
• Use of colorNot relying on hue alone to convey meaning"don't just turn it red" · "color-blind safe"
• WCAGGlobal standard defining accessibility success criteria and levels"the accessibility rules" · "the checklist auditors use"
• :focus-visibleShowing the focus ring only for keyboard, not mouse clicks"outline only when tabbing" · "no ugly ring on click" · "focus-visible"
• Target sizeMinimum tappable area so controls aren't too small to hit"the button's too tiny to tap" · "fat finger space"
• Error identificationNaming what went wrong in a form, not just coloring it red"tell them what's broken" · "actual error message"
• Prefers-reduced-motionSystem setting asking sites to tone down animation"for people who get motion sick" · "turn off the animations setting"
• Resize text and reflowLayout still works at 200-400% magnification without horizontal scroll"when they blow up the text" · "browser zoom doesn't break it" · "zoom and reflow"
• CaptionsSynchronized on-screen text of speech and sound in video"subtitles for deaf people" · "the words on the video"
• Decorative imageMarking purely visual images empty so readers skip them"images that shouldn't be announced" · "ignore this picture"
• Assistive technologyUmbrella for screen readers, magnifiers, switches, voice control"the gear disabled users use" · "special software and devices"

Deeper in the field

• ARIA role Attribute declaring what a custom widget is
• aria-expanded and aria-controls State attributes telling readers a disclosure is open
• aria-hidden Removes decorative content from the accessibility tree
• aria-live politeness Whether an update interrupts the screen reader
• Text spacing override Layout survives user-increased line height and letter spacing
• Input modality support Supporting switch, stylus, and voice input equally
• Voice control (speech input) Operating UI by spoken commands matching visible labels
• Switch access Single-button scanning input for motor-impaired users
• Captions and transcripts Timed text versus a full readable text version
• Autoplay control and flashing content Seizure and distraction risks from motion or blinking
• Timeout extension Letting users request more time before a session expires
• Character key shortcuts Single-key shortcuts hijacking assistive tech input
• Screen magnifier Zoom tool where offscreen or low-contrast UI disappears
• Braille display Refreshable tactile output driven by the accessibility tree
• Accessible data table Header scope and captions so cells are announced meaningfully
• Roving tabindex Pattern where arrow keys move within a group, Tab exits it
• Accessibility tree Browser's parallel structure exposing UI to assistive tech
• Audio description Narration track describing key visuals for blind viewers
• Inclusive design Designing for the full range of human ability from the start
• Reading order Sequence in which assistive technology encounters page content
• Link purpose Descriptive link text that clarifies destinations outside surrounding context
• Label in name Visible control text also appears in its accessible name
• Accessible description Extra control instructions exposed to assistive tech, often via aria-describedby
• Name, role, value Controls expose identity, type, state, and changes to assistive technology
• Non-text contrast Contrast requirements for controls, icons, indicators, and meaningful graphics
• Accessible authentication Login flows that avoid memory, transcription, or puzzle barriers
• Error suggestion Telling users how to correct a detected input error
• Error prevention Confirmation or reversal for submissions having serious consequences
• Dragging alternative Non-drag control for actions otherwise requiring pointer dragging
• Pointer gestures Alternatives to multipoint or path-based gestures
• Content on hover or focus Revealed content remains dismissible, hoverable, and persistent when needed