User Agent Firefox extension security report

Some sites still refuse Firefox. SandAgent lets you present a different browser identity — and, unlike most user-agent switchers, it keeps every related value consistent with the one you chose. EVERYTHING FROM ONE SOURCE The User-Agent header and navigator.userAgent are produced from the same value, so they cannot contradict each other. The same goes for the platform, appVersion, vendor, the Sec-CH-UA client hints and navigator.userAgentData. A mismatch between them is the first thing any detection script looks for, and it is the flaw most user-agent switchers ship with. TWO KINDS OF PROFILE, CLEARLY LABELLED Stealth presents you as a different Firefox — a different version, or a different operating system. Because the engine really is Firefox, nothing in the environment can contradict the disguise. Compatibility presents you as Chrome, Edge or Safari. This unblocks sites that read the User-Agent string, which is what most of them do. WHAT IT DOES NOT DO Compatibility profiles do not fool bot-detection systems, and the add-on says so in its own interface. The TLS and HTTP/2 fingerprints are produced by Firefox's network stack, below any extension API, and services like Cloudflare cross-check them against the announced User-Agent. No browser extension can change that. If you want a quiet browsing experience on protected sites, the honest answer is to stay on a Firefox profile. THE RIGHT PROFILE, SITE BY SITE Keep your real Firefox everywhere and put on a Chrome profile only where you need it. A rule covers a domain and all its subdomains, and both the headers and the JavaScript follow it. YOUR OWN USER-AGENT Paste any string. SandAgent uses it verbatim and derives the matching values from it. If it cannot read the string, it says so instead of guessing — no bundled list of user agents, so nothing ever goes stale. BUILT-IN DIAGNOSTIC One click replays, on the current page, the checks a fingerprinting script would run. It reports what is coherent, what is not, and which engine-level tells remain out of reach of any extension. PRIVATE BY DESIGN No account. No analytics. No telemetry. No data collection of any kind. SandAgent makes no network requests of its own; it only modifies requests your browser was already making. Available in English and French.