Free Online User Agent Parser
Detect browser, operating system, device, and engine from a user agent.
A user agent is sent by browsers, bots, and apps with every HTTP request.
Results are best-effort. User agent strings can be edited by the client, and a browser may freeze or reduce the information it sends to protect privacy.
About the User Agent Parser
Every time a browser, crawler, or app makes an HTTP request, it usually includes a User-Agent
header. That string describes the client software: the browser name and version, the rendering engine, the
operating system, the device model, and sometimes the CPU architecture. Server logs, analytics tools, and
support forms collect user agents so developers can understand which environments their visitors use.
This parser uses ua-parser-js, a widely used library with a large set of detection patterns. Paste any user agent string to split it into readable fields, or press Use my browser to analyze the string your current browser sends. The results include browser, engine, operating system, device, and CPU. The JSON view gives you the same data in a machine-readable form that you can copy or download for debugging a support ticket, building a compatibility report, or testing a bot-detection rule.
Reading the result
- Browser: the detected browser family and version, such as Chrome 124 or Safari 17.
- Engine: the rendering engine, such as Blink, Gecko, or WebKit.
- Operating system: the platform name and version, such as Windows 10 or iOS 17.
- Device: the vendor, model, and type when a phone, tablet, or TV can be identified.
- CPU: an architecture hint such as amd64 or arm64. Many modern browsers omit this.
Desktop computers often produce an empty device object because there is no model to report. That is normal and usually means "desktop or unknown device", not that parsing failed. Some browsers reduce the detail in their user agent to avoid fingerprinting, so a field may say Unknown even when the information is obvious to a human reader.
Common uses
- Reproduce a bug reported by a customer on a specific browser version.
- Check whether a crawler or monitoring bot is visiting your site.
- Verify that a mobile emulator is sending the user agent you expect.
- Group traffic by operating system without storing the full request log.
Frequently asked questions
Can I trust the detected browser version?
Treat it as a hint. User agent strings are self-reported and can be spoofed or simplified. Use feature detection for behavior that must be reliable, and use user agent parsing only for analytics, diagnostics, or coarse routing.
Why does my browser show a frozen operating system version?
Browsers such as Safari and Chrome deliberately freeze or reduce parts of the user agent to limit fingerprinting. The real operating system may be newer than the reported version.
Is my user agent sent to a server?
No. The parsing happens locally in your browser. The string is not uploaded by this tool.