Skim Extension
Credibility Analysis Where You Already Read: The Skim Browser Extension.
The extension injects a React interface straight into pages you are already reading. It detects the kind of page you are on, analyses the content, and highlights claimed facts, opinions and dubious claims in place, alongside credibility and bias scores for the source.
It is a Manifest V3 extension built with React, TypeScript and Vite. The injected UI renders inside a Shadow DOM so the host page's CSS can never bleed into it and vice versa, a background service worker coordinates state across tabs, and an embedded iframe hosts the authenticated web experience so a single sign-in carries across the extension and the site.
Platform-specific modules handle YouTube separately from articles, and the highlighting engine has to map analysis results back onto live DOM text that keeps changing as you scroll, move between videos or enter fullscreen. The work has not been purely client-side: keeping it supplied with analysis has also meant implementing changes in the backend services it talks to.
- The problem
- Credibility tooling only helps if it reaches you where you actually read. Asking someone to copy a URL into a separate tab is friction they will not accept every time.
- My approach
- I built a Manifest V3 extension that injects a Shadow DOM-isolated React UI into YouTube and news sites, with a background service worker for cross-tab state and an iframe bridge that shares an authenticated session with skim.plus, along with the changes needed in the backend services behind it.
- The outcome
- Published on the Chrome Web Store, where it is Featured and rated 5.0. The analysis now meets readers on the page instead of asking them to go somewhere else.