Language / Locale Leak
See what your language settings reveal — including through a VPN.
How this test works
The browser's primary language, its full ordered list of preferences, timezone, and number and date formatting are read. The ordered list is the part that matters. Almost everyone shares a primary language with millions of people, so that alone reveals very little — but a list like “en-GB, en, pl” describes a far smaller group than either English or Polish does, and the ordering carries information too. It also survives a VPN completely untouched, because it comes from your operating system rather than from your connection: a browser reporting a Polish preference through a German exit node has just said something the IP address was concealing. Number and date formats leak the same regional information a second time, independently of the language tag.
What the results mean
- Primary language
- Shared with a very large population. Weak on its own.
- Full preference list
- The identifying part. Order and length both narrow the group.
- Number and date format
- Regional signals independent of the language tag.
- Survives a VPN
- Yes. Locale is an operating system setting and the connection has nothing to do with it.
Common problems and fixes
- My VPN is on but my language gives me away
- Expected. A VPN changes the route your traffic takes and nothing about your system settings. Changing the browser's language list is a separate step.
- I only have one language listed
- Slightly unusual in itself, since most systems accumulate fallbacks. Uniformity is not always anonymity.
- Can I change what is reported?
- Yes, in operating system or browser language settings. Some anti-fingerprinting modes report a single generic locale to everyone.
Frequently asked questions
Why is my language list more identifying than my language?
Because sharing English with a billion people reveals nothing, while sharing “en-GB, en, pl” in that order narrows you to a much smaller group. Length and ordering both carry information.
Does a VPN hide my language?
No. Language preferences come from your operating system and are sent by the browser regardless of the route your traffic takes. This is a common and consequential misunderstanding.
Should I change my language settings for privacy?
Only if you accept the cost — sites will render in a language you did not choose. Browsers with strong anti-fingerprinting modes normalise this for you.