Rule pack
Accessibility rules
What a screen reader, a keyboard and a pinch of the fingers make of the page, as far as its HTML can say.
Automated checks find roughly a third of accessibility problems. Passing them is not WCAG conformance; a person with a keyboard and a screen reader finds the rest.
Accessibility
Error The page has no title to announcea11y.page-titleWarning Screen readers can't tell what language the page is ina11y.langWarning Pinch-zoom is switched offa11y.viewport-zoomNotice No main landmarka11y.landmark-mainNotice Headings skip a levela11y.heading-orderWarning Images have no alt texta11y.image-altNotice Alt text that doesn't describe the imagea11y.image-alt-qualityWarning Links with no texta11y.link-nameWarning Buttons with no namea11y.button-nameWarning Form fields without a labela11y.form-labelWarning Frames without a titlea11y.iframe-titleNotice Data tables without header cellsa11y.table-headersWarning Sound may play on its owna11y.autoplayNotice The tab order has been rearrangeda11y.tabindexWarning The same id is used more than oncea11y.duplicate-idWarning ARIA roles that don't exist or are incompletea11y.aria-validWarning Someone has been through the site with a keyboarda11y.keyboard-walkthroughNotice Someone has listened to the sitea11y.screen-reader-pass