What is a user agent string?

A user agent (UA) string is a text identifier that your browser sends in the HTTP User-Agent header with every request. It tells web servers what browser, version, and operating system you are using so they can serve compatible content.

Why do user agent strings look so complicated?

UA strings evolved over decades of browser compatibility hacks. Most modern browsers include tokens from earlier browsers (like 'Mozilla/5.0' or 'like Gecko') to ensure compatibility with servers that check for specific strings.

Can websites use my user agent to track me?

Your user agent string is one of many data points that can contribute to browser fingerprinting. Combined with other signals it can help identify you without cookies, but it is not unique enough to track you reliably on its own.

How can I change my user agent string?

Most browsers allow you to override the user agent in the developer tools (Network conditions panel in Chrome/Edge, Network Monitor in Firefox). Browser extensions can also spoof the UA string.

What is the difference between the browser engine and the browser itself?

The rendering engine (e.g. Blink, Gecko, WebKit) is the code that parses HTML and CSS. The browser (e.g. Chrome, Firefox, Safari) is the application built on top of that engine and adds the interface, extensions, and other features.

Does this tool store my user agent?

No. Your user agent is read locally from the browser's navigator.userAgent property and displayed to you. Nothing is sent to a server or stored.

Yes, completely free with no account, no sign-up, and no usage limits.

Why do some bots send fake user agent strings?

Web scrapers and crawlers often send fake user agents to mimic real browsers and avoid bot detection. Conversely, some legitimate crawlers (like Googlebot) send a distinctive UA so site owners know they are being indexed.

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User Agent Parser

Parse any user agent string into browser, OS, device type, and bot detection.

or try a sample:

Enter a user agent string above to parse it

What is my user agent?: inspect your browser's UA string with full parsed details

Every browser sends a user agent string with each HTTP request, identifying itself to the server. This seemingly cryptic text tells web servers your browser name, version, operating system, and device type. Knowing your user agent is useful for debugging compatibility issues, testing responsive designs, investigating server logs, and understanding what data your browser exposes to websites.

This tool reads your browser's user agent string directly from the JavaScript navigator.userAgent property and parses it into readable fields: no server round-trip required. The full raw string is also shown so you can copy it exactly for use in testing tools, support tickets, or API calls that require a specific user agent.

Step-by-step guide

1
Open the tool
Navigate to this page. Your browser's user agent string is read automatically: no input required.
2
View the full UA string
The complete raw user agent string is displayed so you can inspect or copy the exact value your browser sends to servers.
3
Read the parsed breakdown
The tool parses the UA string and shows individual fields: browser name, browser version, operating system, OS version, and device type.
4
Check rendering engine details
See the underlying rendering engine (e.g. Blink, Gecko, WebKit) and JavaScript engine if detectable from the user agent.
5
Copy the user agent string
Click Copy to put the raw UA string on your clipboard for use in debugging, API calls, or testing tools.

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Frequently Asked Questions

What is a user agent string?: A user agent (UA) string is a text identifier that your browser sends in the HTTP User-Agent header with every request. It tells web servers what browser, version, and operating system you are using so they can serve compatible content.
Why do user agent strings look so complicated?: UA strings evolved over decades of browser compatibility hacks. Most modern browsers include tokens from earlier browsers (like 'Mozilla/5.0' or 'like Gecko') to ensure compatibility with servers that check for specific strings.
Can websites use my user agent to track me?: Your user agent string is one of many data points that can contribute to browser fingerprinting. Combined with other signals it can help identify you without cookies, but it is not unique enough to track you reliably on its own.
How can I change my user agent string?: Most browsers allow you to override the user agent in the developer tools (Network conditions panel in Chrome/Edge, Network Monitor in Firefox). Browser extensions can also spoof the UA string.
What is the difference between the browser engine and the browser itself?: The rendering engine (e.g. Blink, Gecko, WebKit) is the code that parses HTML and CSS. The browser (e.g. Chrome, Firefox, Safari) is the application built on top of that engine and adds the interface, extensions, and other features.
Does this tool store my user agent?: No. Your user agent is read locally from the browser's navigator.userAgent property and displayed to you. Nothing is sent to a server or stored.
Is this tool free?: Yes, completely free with no account, no sign-up, and no usage limits.
Why do some bots send fake user agent strings?: Web scrapers and crawlers often send fake user agents to mimic real browsers and avoid bot detection. Conversely, some legitimate crawlers (like Googlebot) send a distinctive UA so site owners know they are being indexed.

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vs server-side converters: AlteredIdea converts in your browser: your data never leaves your device.

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