User Agent strings contain information about the browser, operating system, device, and rendering engine. Use this tool to debug client detection issues or analyze traffic patterns.
What is User Agent Parser?
A User Agent (UA) string is an HTTP header that browsers and HTTP clients send with every request to identify themselves. It encodes the browser name and version, operating system, device type, rendering engine, and CPU architecture into a single, somewhat chaotic string. UA parsing extracts these components into structured data that you can use for analytics dashboards, browser compatibility warnings, bot detection, and device-specific content delivery. While UA strings can be spoofed and are being phased out in favor of User-Agent Client Hints, they remain the most widely available signal for understanding who is accessing your service.
How to Use
- Paste a User Agent string into the input field, or click Get My UA to automatically load your current browser's UA
- Click Parse to extract browser, operating system, device type, rendering engine, and CPU architecture
- Review the structured output in the detail cards and the raw JSON representation below them
- Use the sample UA buttons to quickly test how different browsers, devices, and bots are parsed
Why Use This Tool?
Tips & Best Practices
- Click Get My UA to instantly see what your browser reports about itself — useful for debugging feature detection
- Use the sample UAs to verify that your server-side detection logic handles edge cases like iPad vs iPhone
- Always treat UA-based detection as a hint, not a guarantee — browsers allow users to override their UA string
- Mobile Android UAs often include the device model name, while iOS UAs only reveal the iOS version
- API clients like curl, axios, and Postman have distinct UA patterns that are easy to filter in server logs
Frequently Asked Questions
What is a User Agent string and where does it come from?
The User Agent string is an HTTP request header that browsers and HTTP clients automatically send with every request. It identifies the client software, operating system, device, and rendering engine. Servers use it for content negotiation, analytics, and compatibility decisions. You can inspect it in browser developer tools via navigator.userAgent.
How do I find my own User Agent?
Click the Get My UA button on this tool to instantly see your current browser's User Agent string. Alternatively, open your browser's developer tools console and type navigator.userAgent, or inspect the User-Agent header in any network request in the Network tab.
Can User Agent strings be trusted for security decisions?
No. UA strings are trivially spoofed — browsers allow custom UA strings via developer tools or extensions, and bots can send any string they want. Use UA parsing for analytics, debugging, and user experience optimization, but never as the sole basis for access control, authentication, or security enforcement.
When should I NOT rely on User Agent parsing?
Do not rely on UA parsing for security-critical decisions like authentication or authorization. Also avoid it when you need guaranteed feature detection — use feature detection (e.g., checking if an API exists) instead of browser sniffing. UA strings are being deprecated in favor of User-Agent Client Hints, which provide more structured and privacy-preserving signals.
Is my data private when using this tool?
Yes. All parsing happens entirely in your browser. When you click Get My UA, the string is read from your browser's navigator object and processed locally. No UA string is ever transmitted to any server, logged, or stored.
What is the difference between Chrome and Safari User Agent strings?
Chrome UAs contain 'Chrome/x.x' and use the AppleWebKit engine. Safari UAs contain 'Safari/x.x' but explicitly lack 'Chrome/x.x' — this absence is the key distinguishing factor. Both browsers use AppleWebKit, but Chrome adds its own identifier. This is why UA parsing checks for the absence of 'Chrome' before identifying Safari.
Real-world Examples
Detecting mobile vs desktop traffic for analytics
A server-side analytics pipeline parses the UA string to classify each request as mobile, tablet, or desktop for reporting.
Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1
{
"browser": { "name": "Safari", "version": "17.0" },
"os": { "name": "iOS", "version": "17.0" },
"device": { "type": "Mobile", "vendor": "Apple" },
"isBot": false
}Identifying a search engine crawler
A web server checks the UA to detect Googlebot and serves a server-side rendered page instead of the JavaScript SPA.
Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)
{
"browser": { "name": "Unknown", "version": "" },
"os": { "name": "Unknown", "version": "" },
"device": { "type": "Bot" },
"isBot": true
}