// the find
gorhill/uBO-Scope
A tool to reveal all the connections -- attempted or successful -- to remote servers.
A browser extension from the author of uBlock Origin that shows you every third-party server your browser touched while loading a page, blocked or not. It's a passive observer, not a blocker — the value is in seeing the actual network surface of a site, including connections that slipped past DNS-level blocking.
Uses the public suffix list correctly to count distinct registrable domains rather than raw hostnames, so a CDN with 12 subdomains counts as one server. Works across all content blockers and DNS filters — it reports what the browser's webRequest API saw, regardless of what blocked what. Available on all four major browsers including Safari via TestFlight, which is rare for a privacy tool. The codebase is small and auditable: five JS files, no framework, no build complexity beyond a Makefile.
367 stars for a gorhill project is low, which tells you this never found its audience beyond power users and filter list maintainers. The README says 'I do not intend to update this extension often' and the last meaningful commit activity confirms it — this is maintained but not actively developed. It can't see requests made outside the webRequest API (service workers with fetch, WebSockets in some configurations, QUIC/HTTP3 in browsers that don't expose it), so the picture it shows is incomplete in ways that aren't obvious. No export or history — once you close the popup, the data is gone.