User agent parser

Paste any HTTP user agent string into this free user agent parser to extract browser, OS, and device details. It works instantly with zero signup required.

How a user agent parser works

The User-Agent header is a messy text string. Browsers and apps just keep appending their own identifiers to it, creating a long chain of tokens separated by spaces and slashes. This online user agent parser breaks that raw string into structured fields. It maps the tokens to known browser engines, operating system versions, and hardware profiles.

The format originally started as a simple product token. Now it contains comments in parentheses and trailing extensions. Parsing this reliably means handling nested parentheses and gracefully falling back when the client sends a malformed header. If you wonder how to parse user agent string data manually, it requires reading RFC 9110.

When to decode a user agent string

You usually need this when debugging web traffic or analyzing server logs. A raw log line gives you the IP address and the timestamp. The user agent string tells you what the client actually is. You might see a 404 error and wonder if it was a bot or a real user on an old iPhone. This tool gives you the answer immediately.

Frontend developers use it to reproduce bugs reported by users. A user says the layout breaks on their phone. They paste the string from their browser console into this free user agent parser. You instantly see they are running an outdated WebView on Android 8. You can then spin up the exact emulator to fix the CSS issue.

• Debugging unexpected 403 or 404 responses in your access logs.
• Reproducing frontend layout bugs reported by specific mobile devices.
• Verifying if a suspicious request comes from a known bot framework.
• Checking the exact OS version of a client reporting a crash.

Limits of parsing user agent strings

This tool only reads what the client sends. It doesn't perform network requests or fingerprint the device via JavaScript. If a client spoofs their header, the parser will happily report a desktop browser. You can't use this to definitively block bots. Security teams rely on this data for initial triage, but a determined attacker will just copy a legitimate string.

Privacy-focused browsers actively freeze or randomize their user agent strings. Brave and Tor Browser often report a generic version to blend in with the crowd. The parser will give you accurate data for that generic string, but it won't reflect the true underlying device. Always treat user agent data as a hint rather than absolute truth.

• Spoofed headers will return spoofed results without warning.
• Privacy browsers return generic strings that hide true device details.
• It cannot detect the actual screen resolution or network speed.

How to use the user agent parser

1. Copy the full user agent string from your browser console, network tab, or server log.
2. Paste the raw text into the input field at the top of the page.
3. Click the parse button to process the string.
4. Review the extracted browser, operating system, and device details in the results panel.
5. Copy the structured JSON or individual fields for use in your own scripts.

Common user agent string components

Here is a breakdown of the typical fields you will see after parsing a standard desktop browser string.

Frequently asked questions

Is this user agent parser completely free?

Yes. You can parse as many strings as you need without creating an account or paying anything. The tool runs entirely in your browser.

How do I find my own user agent string?

Open your browser developer tools and navigate to the Network tab. Reload the page and click on the first request. Look for the Request Headers section to find the User-Agent field.

Why does the parser show the wrong browser for my phone?

Many mobile apps use a system WebView instead of the actual browser app. The string will reflect the underlying Android or iOS system browser, not the app you are currently using.

Can this tool detect if a user is on a tablet?

It tries to identify tablets based on specific tokens in the string. However, many modern tablets send the exact same string as their desktop counterparts, making tablet detection unreliable without client-side JavaScript.