Overlays a panel with Core Web Vitals (TTFB, FCP, LCP, TTI), a visual milestone timeline, page lifecycle milestones, and the 7 slowest resources ranked by duration.
Updated Sep 10, 2026
Lab
Bookmarklets
The browser shows you what the application wants you to see. Testing often starts with what it doesn't.
This is a growing collection of small bookmarklets for looking beneath the surface, questioning what you find, and turning the browser into a testing playground. Drag one to your bookmarks bar, click it, and start exploring.
Image generated by AI
Reads a JWT from localStorage (WWW-Authenticate key), decodes it locally, and shows a panel with expiry status, algorithm, issuer, subject, issued/expires timestamps, and expandable JSON for the header, payload, and signature.
Updated Sep 10, 2026
Overlay panel for GitHub PRs that pages through all paginated comments, bulk-resolves open conversations with live progress, and expands or collapses resolved threads.
Updated Sep 10, 2026
Outlines every interactive element: green where a stable test selector exists, red where automation would fall back on text or position.
Updated Sep 10, 2026
Numbers every focusable element in tab order, draws an SVG arrow path showing the flow, flags tabIndex > 0 violations, and tests each element for a visible focus ring.
Updated Sep 10, 2026
Mutate the running page to reach states the app normally prevents: reveal hidden elements, unlock disabled controls, remove validation, bypass form submission, and chaos-test with page-wide presets — all undone by a reload.
Updated Sep 11, 2026