User-agent parser · Guide
User-Agent Parser Online: Browser, OS and Device
A user-agent parser breaks the cryptic UA string a browser sends into readable fields: browser, version, OS, device and rendering engine. This guide explains the string and how parsing helps.
Making sense of the UA string
The user-agent string is a dense, historically messy line that identifies the client. A parser extracts the meaningful parts — which browser and version, which OS, what kind of device — so you do not have to decode it by eye.
It runs in the browser, so UA strings pulled from logs or support tickets stay local.
Heuristic by nature
UA parsing is best-effort: the strings are inconsistent and some clients spoof them. Treat results as a strong hint rather than absolute truth, especially for unusual or old clients.
Frequently asked questions
Is user-agent parsing always accurate?
No. UA strings are inconsistent and can be spoofed, so parsing is heuristic. It is reliable for mainstream browsers but can misread unusual or deliberately altered strings.
Ready to try it?
Open the free browser-based User-agent parser and apply what you just read — no sign-up, runs locally.
Open the User-agent parser tool