External Domain Check

See what external domains a page uses. Scan again after a change to spot what's new, removed, or different.

External Domain Check helps web developers, QA engineers, agencies, and privacy-minded site owners answer one question after a release or website change: did the set of external domains this page talks to change? Open a page you own, maintain, test, or are otherwise authorized to inspect, click the extension, and choose Scan page. Save the external domains it normally uses as a baseline. After a deploy or other change, scan the same page again to see exactly what's new, what's no longer there, and what's being used differently (script, stylesheet, font, image, media, iframe, fetch/XHR, beacon, other) — compared with the exact, precise value (protocol, hostname, and port) underneath, for anyone who needs it. Nothing is applied automatically: you decide whether a difference is expected, and only you can choose to use a new scan as the updated baseline, with every earlier baseline kept in local history and restorable anytime. Export a saved check as JSON, or copy a plain-text comparison report. A new domain is never described as malicious, unsafe, or non-compliant — only as a change from what you told the extension to expect. This is an on-demand check, not continuous monitoring: scanning only happens when you click Scan, nothing runs in the background, and all data stays on your device.