Site Domains Explorer by communism420

Site Domains Explorer shows which first-party and third-party hostnames a website uses while it loads.

It combines Firefox network events, Resource Timing, page resource scanning, and a packaged observer for dynamic requests to discover hostnames used by scripts, images, fonts, iframes, APIs, CDNs, WebSockets, trackers, and other resources.

Features:
- near-real-time hostname discovery;
- separate first-party and third-party results;
- copy first-party, third-party, or all hostnames;
- searchable and expandable local history;
- per-site domain lists and visit information;
- one-click history deletion with confirmation;
- interfaces in English, Spanish, German, Portuguese (Brazil), Russian, Ukrainian, and French.

Automatic collection is disabled until the user explicitly accepts the first-run disclosure. Browsing records contain only hostnames, visit timestamps, and visit counts. The interface language and consent choice are also stored locally.

The extension has no analytics, advertising, account system, remote code, or external data server. It is fully open source under the MIT License.