Page Diff Watcher
Tells you what changed on a page since you last looked.
What you're making
Watch any page — a job board, a docs page, a course listing — and this checks it periodically and highlights exactly what changed. Not 'something changed', but the actual added and removed text, marked up on the page itself. Useful for anything that updates without telling you.
An extension that snapshots page content, re-checks on a schedule, and renders a visual diff of what changed. Ignoring noise — timestamps, adverts, rotating banners — is what makes it usable.
Hosting · Free forever
Deploys free on Firefox Add-ons or GitHub Releases.
Firefox's store is free. Chrome's charges a one-off developer fee, so ship Firefox first if you'd rather pay nothing.
Free on Firefox Add-ons; Chrome's store charges a one-off developer fee.
Core features · 7
- Watch the current page with one click
- Re-checks on a schedule in the background
- Highlights added and removed text on the page
- Ignores noisy regions like timestamps and adverts
- Notifies only when something meaningful changed
- Keeps a short history of past versions
- Lets you select just a region of the page to watch
The interesting part
- Almost every page changes trivially on each load, so noise filtering is the product
- Storing enough snapshots to diff without filling browser storage
- Anchoring highlights to text after the page structure shifts
Once it works
- Watch behind a login using your existing session
- Add a keyword trigger that only fires on certain words
- Export change history as a feed