All 29 UltraDevKit tools

Every tool runs locally in your browser, on any website — including staging environments behind a login. One extension instead of a dozen bookmarklets and tabs.

Inspect & Debug2 tools

Click any element to see its computed styles, then edit them live with sliders and colour pickers. Change padding, colours, fonts, borders and shadows on a real page and watch the result instantly — no DevTools panel required.

How to use CSS Inspector ›

Design & Layout7 tools

Outline every element on the page to expose the box model and spot layout bugs, overflow and stray containers instantly.

How to use Outline ›

Force a dark theme on any website that does not ship one, with adjustable intensity and warmth. Images and video stay natural instead of being inverted.

How to use Dark Mode ›

Accessibility3 tools

Scan any page for WCAG problems — missing alt text, unlabelled form controls and buttons, skipped heading levels, low-contrast text, missing landmarks and duplicate IDs. Each issue is scored by severity, highlights the element on click, and exports as JSON.

How to use Accessibility Audit ›

Audit & Analysis6 tools

Audit a page's title, meta description, canonical URL, Open Graph and Twitter card tags, headings and structured data, with warnings for anything missing or over length.

How to use SEO Inspector ›

Capture & Export3 tools

Live Editing3 tools

Rewrite any text on a live website to preview copy changes before they ship. Ideal for checking how longer headlines wrap or how a shorter CTA looks in context.

How to use Text Editor ›

Developer Utilities5 tools

Send GET, POST, PUT and DELETE requests with custom headers and bodies, and read formatted JSON responses without leaving the tab you are working in.

How to use API Tester ›

Get all 29 tools

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Install from the Chrome Web Store