🔍 User Agent Parser — Parse Browser, OS & Bot
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Paste any User-Agent string to identify the browser, operating system, device, and whether it is a known bot. Free, browser-based, works offline.
A User Agent Parser reads the User-Agent string a browser sends with each request and breaks it into browser, version, engine, operating system, device type, and bot status. This tool parses any pasted string entirely in your browser — nothing is sent to a server. Results are best-effort pattern matching, not guaranteed identity, because User-Agent strings can be spoofed.
📋 When to Use the User Agent Parser
The User Agent Parser is for developers and site owners who work with server logs, analytics, or bot traffic. Paste a User-Agent line from an access log to answer "is this a real visitor or a crawler?" — the tool names Googlebot, Bingbot, GPTBot, AhrefsBot, and other bots instead of just echoing your own browser. Use it during debugging, when reviewing suspicious traffic, or when you need a quick machine-readable breakdown of any pasted string. Unlike "what's my browser" pages, it is not limited to your own User-Agent: you can paste third-party, spoofed, or server-log strings. Your User-Agent string is parsed entirely in your browser and never sent to any server. No registration, no cookies from this tool.
⚙️ How the User Agent Parser Works
The tool reads your pasted string with zero-dependency vanilla regular expressions and splits it into browser, version, engine, operating system, device type, and bot status. A fixed detection matrix checks for crawler tokens such as Googlebot, Bingbot, GPTBot, AhrefsBot, SemrushBot, MJ12bot, Baiduspider, YandexBot, and DuckDuckBot, then returns isBot: true plus the bot name. Device detection sets the isMobile and isTablet boolean flags from mobile, tablet, and touch tokens. All parsing runs synchronously in client-side JavaScript — nothing is sent to a server. A User-Agent string is client-controlled and can be spoofed; results are best-effort pattern matching, not a guarantee of identity.
Because a User-Agent is a request header, you may also want to inspect the HTTP response headers a server returns, or see the IP address your browser exposes — the other half of the identity a browser leaks to the web. Once you know which bots are hitting your site, control which bots may crawl your site and test whether Googlebot can crawl a URL.
How to Use the User Agent Parser
- Paste a User-Agent string — paste a User-Agent string into the box, or click Use my UA to grab your own browser's string.
- Click Parse User-Agent — the tool splits the string into browser, version, engine, operating system, and device.
- Review the result — the summary and JSON output include isMobile, isTablet, and isBot boolean flags.
- Copy or share — copy the JSON, download it, or turn the JSON output into a TypeScript interface for your own tooling.
Frequently Asked Questions
What is a User-Agent string?
A User-Agent string is a line of text your browser sends with every HTTP request. It identifies the browser, engine, operating system, and device to the server. This tool reads that string and breaks it into those fields.
How do I find my own User-Agent?
Copy it from your server logs, or open DevTools (F12) and type navigator.userAgent in the console. On this page, click the Use my UA button to fill the box automatically.
What does 'Windows NT 10.0', 'like Gecko', or 'like Mac OS X' mean?
Windows NT 10.0 is the internal name for Windows 10 and 11. 'like Gecko' and 'like Mac OS X' are backward-compatibility tokens that let old UA-sniffing code keep working.
Can a User-Agent be faked or spoofed?
Yes. The User-Agent is fully client-controlled — a browser, extension, or bot can send any string it wants. This tool's result is best-effort pattern matching, not a guarantee of identity.
How do I tell if a visitor is a bot from the User-Agent?
Look for crawler tokens like Googlebot, Bingbot, GPTBot, or AhrefsBot. This tool flags them with isBot: true. Bots can also spoof a real browser's User-Agent, so pair it with IP and behavior checks.
How do I change my User-Agent?
In Chrome or Edge DevTools, open Network conditions, untick 'Use browser default', and pick a User-Agent. You can also use a UA-switcher extension or launch a browser with a --user-agent flag.
Cite this tool
@misc{toolstand_useragentparser,
title = {User Agent Parser},
author = {{ToolStand}},
year = {2026},
url = {https://toolstand.io/tools/user-agent-parser/}
}Using this tool in a post or paper? Copy a ready-made reference above.
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