Browser Inspector
Everything this page can honestly tell about the browser it is running in: how it got here, what it stores, what it has been given permission to do, what it leaks, and how identifiable it is. Then a report you can hand to somebody.
Nothing is sent anywhere. Every check runs in this tab, and the report is only in this page until you copy it.
What a web page cannot see
Said plainly, because tools that imply otherwise are selling something.
- Your installed extensions. There is no interface for listing them, on purpose — it would be a gift to every fingerprinting script on the internet. What can be seen is the traces an extension leaves on this page: marks on the document, and native functions that have been replaced. Both are reported above when they appear.
- Permissions you have given other sites. A page can read its own origin's permissions and nothing else. If the camera says "granted" above, that is this site — and this site has never asked for it.
- Your antivirus, your firewall, your patch level, your other tabs. None of it is exposed to a web page, and any site claiming to have scanned your machine is guessing or lying.
- Whether your browser is genuinely up to date. The version below is what the browser reports, and a browser can be made to report anything. Check it against the browser's own about page.