Robots.txt Generator
A robots.txt generator is a tool that writes the plain text file crawlers read at the root of your site…
Free user agent parser
Paste a user agent string and see the browser, operating system, device and any known bot.
Paste the User-Agent value from your server log, analytics export or browser. Nothing is sent anywhere; parsing happens in your browser.
Result
0Browser
0Operating system
0Device type
| Field | Value |
|---|
The free user agent parser runs in your browser, needs no sign-up and never sends what you type anywhere.
Quick answer
A user agent parser reads the User-Agent header a browser or bot sends and splits it into browser, version, engine, operating system and device type. It also flags crawlers such as Googlebot, Bingbot and GPTBot. Treat the result as an estimate: browsers now freeze some details, and any script can fake a bot name.
What is a user agent parser?
A user agent parser is a tool that turns a raw User-Agent string into readable parts. It matches known tokens in order: bot names first, then browser tokens such as Edg/, Firefox/, Chrome/ and Safari's Version/, then platform tokens such as Windows NT, Android and iPhone OS.
How do you use the User Agent Parser?
- Copy a User-Agent value from your server access log, analytics export or a browser's developer tools.
- Paste it into the box, or pick one of the examples to see how parsing works.
- Read the summary line and the stats for browser, operating system and device type.
- Check the table for version, rendering engine and any bot owner and purpose.
- Follow the tips: verify claimed bots by IP or reverse DNS before you block or whitelist them.
What is a user agent string?
A user agent string is a line of text in the User-Agent HTTP header that tells a server which browser, operating system and device made a request. Most browsers follow the pattern Mozilla/5.0 (system) platform (details) extensions, as explained in MDN's User-Agent reference. Bots add their own token, such as Googlebot/2.1.
How do I know if a visit is really Googlebot?
A user agent alone never proves a visit came from Google, because anyone can copy the Googlebot string. Google's documented check is a reverse DNS lookup on the IP that must end in googlebot.com, google.com or googleusercontent.com, followed by a forward lookup that returns the same IP, or a match against Google's published IP ranges.
Why does my user agent show Android 10 or Mac OS X 10_15_7?
Modern browsers freeze parts of the user agent to reduce fingerprinting, so many real devices report Android 10; K or Mac OS X 10_15_7 whatever their true version. Chrome also sends only the major version number. Servers that need exact details can request User-Agent Client Hints instead.
Quick reference
| Token in the string | What it usually means | Watch out for |
|---|---|---|
| Edg/143.0 | Microsoft Edge 143 | Edge also contains Chrome/ and Safari/ tokens |
| Chrome/143.0.0.0 | Chrome or a Chromium browser | Minor version is always 0.0.0 after UA reduction |
| Version/18.6 ... Safari/ | Safari 18.6 | Chrome strings also contain Safari/ |
| Firefox/144.0 | Firefox 144 | FxiOS/ is Firefox on iPhone |
| Windows NT 10.0 | Windows 10 or 11 | The string cannot tell 10 and 11 apart |
| Googlebot/2.1 | Google's main search crawler | Easy to fake; verify the IP |
Worked example
Example
Example: the string "Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.7390.122 Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)" parses as Googlebot Smartphone: a Chrome 141 based renderer, Android token, Mobile device. In a client's log audit I would then run a reverse DNS lookup on the IP before counting it as real Googlebot crawl activity.
Learn more
Frequently asked questions
Is this user agent parser accurate?
It is accurate for common browsers and documented crawlers, but every parser is pattern based. Browsers freeze versions, apps add custom tokens and bots can pretend to be browsers, so treat the output as a good estimate rather than proof of who sent the request.
Does this tool send my user agent anywhere?
No. The parser runs entirely in your browser with JavaScript. The string you paste is never uploaded, logged or stored, so you can safely paste lines from private server logs.
Can I find my own user agent here?
Yes. Open your browser's developer tools, look at any request's headers and copy the User-Agent value, then paste it here. You can also type navigator.userAgent in the console to print it.
Why does Edge show Chrome in its user agent?
Edge is built on Chromium, so its string includes Chrome/ and Safari/ tokens for compatibility, plus its own Edg/ token at the end. Parsers check for Edg/ before Chrome/, which is why this tool reports Microsoft Edge correctly.
Should I block bots by user agent?
Blocking by user agent stops honest bots but not fake ones, because spoofers simply change the string. For crawlers that follow robots.txt, a Disallow rule is cleaner. For abusive traffic, block by verified IP or use your firewall or CDN bot controls.
What is the difference between user agent and client hints?
The User-Agent header sends one long string with every request. User-Agent Client Hints are separate Sec-CH-UA headers that a server asks for with Accept-CH, giving exact details such as platform version only when needed. Chrome and Edge support them; Firefox and Safari do not.
Sources
Facts checked against these official pages. Read how I check facts in my editorial policy.
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