Read a user-agent string

How User-Agent Parser works

The request is made by your browser, so the answer is genuinely yours — your IP, your route, your speed. A server-side check would report the server's connection instead. That difference is the whole reason these pages exist.

That is the whole architecture: static files, one script, no upload endpoint to leak or log. Close the tab and the work is gone.

What the string actually is

A user-agent is one line of text the client sends with every request, and it is a historical accident: browsers kept appending tokens so that old servers would not break, which is why a modern Chrome still claims to be Mozilla, AppleWebKit and Safari before mentioning itself.

Browsers have started fighting back. Chrome freezes minor versions, Safari reports a fixed version string, and the reduced user-agent in Chromium drops the platform detail entirely. That is a deliberate anti-fingerprinting move, and it means a parser will sometimes honestly report less than you hoped.

Why it is a hint, not proof

The header is written by the client. Anything can claim to be anything, which is why bot detection based on user-agent alone is trivially defeated and why support flows should treat the result as a starting point for diagnosis rather than as identity.

The parser here matches locally against a table of patterns and keeps nothing. If you are triaging a ticket, the browser and OS fields are usually enough to reproduce the problem; the engine field matters mainly when a CSS feature is missing.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions