Landmark roles (or “landmarks”) programmatically identify sections of a page. Landmarks help assistive technology (AT) users orient themselves to a page and help them navigate easily to various sections of a page.
They also provide an easy way for users of assistive technology to skip over blocks of content that are repeated on multiple pages and notify them of programmatic structure of a page.

Landmarks Bookmarklet for Accessibility Testing

Highlights all ARIA landmarks, including HTML5 tags that are interpreted as landmarks

Landmarks Bookmarklet Code

See the Pen Landmark Bookmarklet by HolisticA11Y by HolisticA11Y (@HolisticA11YHub) on CodePen.

We hope these accessibility bookmarklets come in handy during your next accessibility audit.

Reference: Accessibility Bookmarklets