What Changed

What Changed automatically snapshots every page you visit and shows you exactly what's different when you return, word by word.

No setup. No watchlists. No polling. Just browse as usual, and the extension runs in the background.

How it works

1. Visit any page. The extension silently captures the main content.
2. Come back later. If anything changed, the badge lights up.
3. Open the side panel to see a clean, word-level diff. Additions in green, removals in red.

Why it matters

Pricing pages quietly raise prices. Terms of service change overnight. News articles get edited after publication. Job listings update requirements. You'd never notice unless something is watching for you.

Features

- Word-level diffs powered by Mozilla Readability and jsdiff
- Smart extraction strips out ads, navigation, timestamps, and noise (only real content changes surface)
- Significance scoring filters out trivial edits and A/B tests
- SPA support detects client-side navigation in single-page apps
- Configurable retention period (7 days to 1 year), significance threshold, and domain blocklist
- Automatic deduplication — unchanged revisits use zero additional storage
- Works on every page automatically. No configuration required.

Private by design

All data stays in your browser's local storage. Nothing is ever sent to a server. No accounts. No analytics. No tracking. Your browsing data never leaves your machine.

Open source: https://github.com/Surfrrosa/what-changed