That was a real bug, fixed in v0.0.63 — update if you're on something older.
The language reached Accept-Language and navigator.languages, but the browser's own locale was never set, so Intl stayed on the machine's locale and every date a page formatted came out American. A British browser writing 1/15/2026 is a contradiction any page produces without trying — no fingerprinting script needed.
The fix passes your profile's language to the browser as its UI locale. The same profile now reports en-GB, 15/01/2026, 13:05:00.
To check any profile, open the console and run:
[navigator.language, Intl.DateTimeFormat().resolvedOptions().locale, new Date().toLocaleDateString()]
The first two should match, and the third should look the way the first implies.
More detail: https://parallel-browser.com/learn/language-locale-mismatch
The language reached Accept-Language and navigator.languages, but the browser's own locale was never set, so Intl stayed on the machine's locale and every date a page formatted came out American. A British browser writing 1/15/2026 is a contradiction any page produces without trying — no fingerprinting script needed.
The fix passes your profile's language to the browser as its UI locale. The same profile now reports en-GB, 15/01/2026, 13:05:00.
To check any profile, open the console and run:
[navigator.language, Intl.DateTimeFormat().resolvedOptions().locale, new Date().toLocaleDateString()]
The first two should match, and the third should look the way the first implies.
More detail: https://parallel-browser.com/learn/language-locale-mismatch