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Browser fingerprint lab

JS engine

The UA string's claim does not count: V8, SpiderMonkey and JavaScriptCore differ in error-message wording, Error.stack format, native toString formatting and a few libm edge values, none of which a fake UA can change.

Running…
Result
Details
Detected engine
Engine claimed by UA
Consistency
Evidence
What this means

When the detected engine differs from the engine the UA claims, the browser is disguising itself, typically an anti-detect profile that runs on Chromium but claims Firefox or Safari. The verdict relies on engine behaviour only, never on easily forged objects like window.chrome; when the probes contradict each other it says unknown instead of guessing.