User Agent Parser
Parse a user-agent string to identify the browser, operating system and device it describes.
Decoding that cryptic string
A user-agent string is the long, messy line a browser sends to identify itself, and it is almost unreadable by eye — packed with version numbers and legacy tokens kept for compatibility. This parses it into the parts that matter: the browser and its version, the operating system, and the device type, so you can make sense of one from a log or a request.
Paste the user-agent string and it is broken down for you.
Why they're such a mess
User-agent strings are notoriously convoluted for a historical reason: browsers spent years pretending to be each other for compatibility, so nearly every modern browser's string still contains tokens like Mozilla and often several other browsers' names. That is why parsing one by hand is so confusing. It is worth knowing, too, that a user-agent can be freely faked, so it is fine for analytics and debugging but should never be trusted as a security check.
Questions & answers
Why do user-agent strings contain other browsers' names?
For historical compatibility — browsers imitated each other, so nearly every string still carries legacy tokens like Mozilla.
Can I trust a user-agent for security?
No — it can be freely faked. It is fine for analytics and debugging, but never for a security decision.
Is anything uploaded?
No. The parsing happens in your browser.