wcag

A perceptual contrast algorithm proposed for WCAG 3 that scores a text and background pair as an Lc value and takes font size and weight into account.

A number from 1:1 to 21:1 describing how far apart two colours sit in relative luminance, used to decide whether text on a background is readable.

The brightness of a colour measured on a 0 to 1 scale after each channel is linearised, which is the input every WCAG contrast calculation actually uses.

A sign-in route that never requires a cognitive function test such as recalling a password or solving a puzzle without offering an alternative.

The text alternative that stands in for an image, written to serve the same purpose in the same context rather than to describe every detail.

A way to stop sound that started on its own, because autoplaying audio drowns out the screen reader voice a reader depends on to find the control that stops it.

A narration track describing visual information the soundtrack leaves out, fitted into the gaps between dialogue.

Synchronised text for a video's audio, including speaker changes and meaningful sound, distinct from subtitles which only translate dialogue.

A shift big enough to disorient a reader, a new page, a new window, a moved focus, a rearranged form, and the rule that it should follow a request rather than a keystroke.

Single letter shortcuts that fire without a modifier, which must be switchable off or remappable because speech input and screen readers trigger them by accident.

The A, AA, or AAA tier a WCAG success criterion sits in, and the tier a product claims, which is what people mean when they say a design is AA.

Keeping the same help route, a contact link, a chat launcher, a self-help pane, in the same relative place on every page so a stuck reader can find it again.

Calling the same function by the same name and icon everywhere in a product, so a reader who learned it once does not have to relearn it per screen.

A second, non-dragging route to anything a drag can do, such as arrow keys or a move-to menu on a sortable list.

Naming the field that failed and saying what went wrong in text, rather than only outlining the input in red.

Content that flashes more than three times per second in a large enough area, restricted because it can trigger seizures.

The size and contrast a focus indicator must reach to count as visible: enough area around the control, enough change against both the control and its background.

The requirement that a focused control is not completely hidden by sticky headers, footers, cookie bars, or chat widgets when it receives focus.

The sequence keyboard focus follows through a page, which should match reading order instead of source quirks or positive tabindex values.

A statement of the gap between what a person can do and what a design demands, the WCAG 3 draft's way of naming a barrier without sorting people into disability categories.

The three conditions content revealed on hover or focus must meet: reachable with the pointer, dismissible without moving focus, and not self-closing.

Text baked into a raster image, which cannot be resized, restyled, selected, translated, or read by anything but the alt attribute someone remembered to write.

Machine readable autocomplete tokens on personal fields, which let browsers autofill and let personalisation tools add familiar icons or wording.

A place keyboard focus can enter but not leave by keyboard alone, stranding anyone who is not using a pointer.

The rule that a control's accessible name must contain its visible label text, so speaking the visible words works in voice control.

The size at which text counts as large for contrast purposes (about 18pt, or 14pt when bold) and its required ratio drops from 4.5:1 to 3:1.

Whether a link's own text says where it goes, the reason a list of read more and click here links fails when read out of context.

Triggering a function by moving the device itself, such as shake to undo, which needs a plain control alternative and an off switch.

The requirement that controls, focus indicators and meaningful graphics reach 3:1 against what is next to them, which is the rule that governs borders and icons.

Restricting a screen to portrait or landscape, which strands anyone whose device is fixed in a mount or a wheelchair arm in the orientation the design refused.

A visible control for content that moves, blinks, scrolls, or updates on its own, so a reader can stop it before reading around it.

Writing interface copy at the reading level of the people using it, with short sentences, familiar words, and the point first, rather than at the level of the org chart.

Activating a control on pointer release rather than press, so someone who lands on the wrong target can slide off and abort.

Path based or multi finger gestures such as pinch, swipe, and drag along a track, which need a single pointer equivalent to stay operable.

The four principles WCAG is built on, perceivable, operable, understandable, and robust, used as a shorthand for sorting an accessibility problem into a bucket.

A user preference asking interfaces to cut non-essential animation, honoured by shortening, cross fading, or removing movement rather than by doing nothing.

The rule against asking for the same information twice in one process, unless it is re-entered for a real reason such as confirmation.

The requirement that content works in one column at 320 CSS pixels wide without two dimensional scrolling, which is 400 percent zoom on a desktop.

Text must scale to at least 200 percent without loss of content or function, which rules out fixed pixel heights around wrapping copy.

Instructions that lean on shape, size, position, or sound alone, such as the round button on the right, which fail when those cues are not perceived.

A signed track alongside video, presented as an inset or a companion stream, for readers whose first language is a sign language rather than the written caption text.

A link at the very start of a page, revealed on focus, that jumps past repeated navigation to the main content.

A change in content that reports progress, result, or state and must be announced without taking focus, such as a count of search results.

The exception that lets an undersized control pass when no other target falls inside a 24 pixel circle centred on it, trading size for clearance.

The requirement that a reader can increase line height, letter spacing, word spacing, and paragraph spacing without any content being lost or clipped.

A warning before a session or form expires with a simple way to extend it, so a slower reader does not lose their work silently.

The minimum area a control must offer a finger or imprecise pointer, measured on the activation region rather than the painted glyph.

A full text version of time based media, readable without playing it and searchable by both people and machines.

The rule that colour must never be the only carrier of meaning, so a red field also needs an icon, wording, or shape change.