Technical and design
User-Agent Parser
Read the browser, system, device type and engine from one or many user-agent strings.
Runs in your browser; nothing is uploaded. · Free, no account · 1 min
Copy it from a server log, the User-Agent request header, or navigator.userAgent in the browser console.
Importing a saved run into your account is coming soon. Until then, your last runs stay in this browser only, and you can download your files.
How to use
- Copy user-agent strings from your server logs or analytics, one per line.
- Paste them into the box.
- Read the table of browser, version, system, device type and engine.
- Treat any crawler identified by name as a claim, and verify it before you trust it.
What it checks and how it works
The tool parses each string with Bowser, an open-source (MIT) user-agent parser, and shows the browser, version, operating system, device type and rendering engine. A string that Bowser names as a crawler is counted as one.
A user-agent string is a claim that the client makes. MDN describes the header as a characteristic string that lets servers identify the application, operating system and version of the requester, and Google verifies Googlebot with a reverse and forward DNS lookup or by matching its published IP ranges, because anyone can send a string that says Googlebot. Browsers now send reduced user-agent strings: Chrome keeps the major version and shows zeros for the rest, which the tool points out, and servers that need more detail ask for User-Agent client hints.
Limits: Bowser recognizes a fixed list of browsers and crawlers, so a new, custom or cut-off string may not be identified. The tool never fetches an address and never checks IP ranges.
Sources
- MDN Web Docs: User-Agent header opened 29 Oct 2026
- Google Search Central: Verifying Googlebot and other Google crawlers opened 29 Oct 2026
- Bowser (npm package, MIT): a browser detector opened 29 Oct 2026
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Questions
About this tool
No. The client sends it and anyone can change it, so a crawler name proves nothing until you verify the visitor, for example with the reverse DNS check Google documents for Googlebot.
Chrome now sends a reduced user-agent string with the major version and zeros for the rest. Sites that need detail use User-Agent client hints, as MDN explains.
Yes. Paste one string per line and the table lists each, with all parsing done in your browser.
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