About User-Agent Parser — Online UA Decoder & Lookup
A User-Agent string is the line a browser, app, or bot sends with every HTTP request to identify itself. Buried in that one dense string are the browser and its version, the rendering engine, the operating system, the device type, and the CPU architecture — but the format is a tangle of historical "Mozilla/5.0" cruft that's hard to read by eye.
This free User-Agent parser decodes any UA string into clean, labelled fields: browser, engine, OS, device, and CPU. It also flags known bots and crawlers — Googlebot, bingbot, and friends — so you can tell real visitors from automated traffic at a glance.
Everything runs entirely in your browser. Nothing you paste is uploaded, which makes this a safe way to inspect User-Agents straight out of analytics logs or server access logs.
Features
- Decode browser, engine, OS, device type, and CPU from any UA string
- Recognizes common bots and crawlers (Googlebot, bingbot, and more)
- One click to parse your own browser's User-Agent
- Fully offline — your input never leaves your device
How to use
- Paste a User-Agent string into the input bar.
- Or click “Use my browser's UA” to parse your own.
- Read the decoded browser, engine, OS, device, and CPU cards.
- Copy any individual field with its copy button.
Frequently asked questions
What is a User-Agent string?
It is a header sent with every web request that identifies the client — the browser name and version, the engine, the operating system, and often the device. Servers use it to tailor responses and analytics tools use it to break down traffic.
How does this parser detect bots?
It matches the UA against a table of known crawler and automation tokens (Googlebot, bingbot, Baiduspider, curl, python-requests, and others) and against generic markers like "bot", "spider", and "crawler". Matches are labelled with a device type of "bot".
Why does my Chrome UA also mention Safari and Mozilla?
For historical compatibility, almost every browser claims to be "Mozilla/5.0" and Chromium-based browsers include "Safari" in their UA. The parser resolves the most specific real token, so a Chrome string is reported as Chrome, and Edge or Opera win over Chrome when their tokens are present.
Is my User-Agent data sent to a server?
No. Parsing happens locally in your browser with hand-written matching logic — there is no API call and no upload. You can use it offline.
Can it identify every possible User-Agent?
It covers the major browsers, engines, operating systems, devices, and bots. Very rare or deliberately spoofed strings may resolve only partially; unknown fields are simply left blank rather than guessed.
Related tools
Everything runs locally in your browser — your input is never uploaded.