User Agent Parser

Parse and analyze user agent strings

Developer Tools

How to Use User Agent Parser

  1. 1Your current user agent is pre-filled
  2. 2Paste any custom user agent string
  3. 3See the parsed components instantly

About User Agent Parser

User Agent Parser decodes the User-Agent HTTP header string and extracts structured information: browser name and version, operating system, device type (mobile, tablet, or desktop), and rendering engine. Paste any user agent string to analyze it instantly.

User agent strings are sent with every HTTP request and are notoriously verbose and hard to read. This tool translates them to plain language in one step. Your current browser's user agent is pre-filled automatically.

You can also paste any custom user agent string from logs, analytics tools, or test suites to analyze it.

Key Features of User Agent Parser

  • Pre-fills your current browser's user agent for instant inspection
  • Extracts browser name and version from any user agent string
  • Identifies operating system and OS version
  • Detects device type: desktop, mobile, or tablet
  • Shows rendering engine (WebKit, Gecko, Blink)
  • Supports any user agent string from logs or analytics tools
  • Works entirely in-browser — no server requests
  • One-click copy for the full parsed summary

Examples

Parse a mobile Safari user agent from an access log

Identify the device and browser from a user agent string in a server access log.

Input

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

Output

Browser: Safari 17.0 | OS: iOS 17.0 | Device: iPhone (Mobile) | Engine: WebKit

Identify a headless Chrome bot user agent

Detect automated headless browser activity by parsing its user agent string.

Input

Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/120.0.0.0 Safari/537.36

Output

Browser: Headless Chrome 120 | OS: Linux x86_64 | Device: Desktop (Headless)

Common Use Cases

  • Analyzing user agent strings from web server access logs to understand visitor devices
  • Debugging browser-specific issues by inspecting the exact user agent
  • Validating user agent parsing logic in web analytics implementations
  • Identifying bot or automated browser traffic from headless Chrome or Puppeteer
  • Testing mobile detection logic by analyzing mobile user agent strings
  • Understanding the user agent format when implementing server-side parsing

Troubleshooting

Browser version shows as unknown

Solution

Some browsers use non-standard version strings. Modern browsers also participate in user agent reduction. The raw string is always displayed for direct inspection.

Device type is detected as desktop on a mobile device

Solution

Some mobile browsers report desktop-like user agents. Check the full user agent string for 'Mobile', 'Android', or 'iPhone' tokens.

Chrome user agent shows as Safari

Solution

Chrome's user agent contains 'Safari' for historical compatibility. The distinguishing token is 'Chrome/'. The parser correctly identifies Chrome by looking for this token first.

Frequently Asked Questions

What information is extracted from a user agent?

Browser name and version, operating system, device type (desktop, mobile, or tablet), and rendering engine. The raw user agent string is also displayed.

Why do most user agents start with "Mozilla/5.0"?

"Mozilla/5.0" is a historical artifact. Early browsers impersonated Netscape for compatibility. Modern browsers continue this convention.

Can I detect Chrome vs Chromium vs Edge from the user agent?

Yes. Chrome, Chromium, Edge, and Opera include distinctive tokens (Chrome, Edg, OPR) in their user agent strings.

Is user agent detection reliable for production use?

User agent parsing is useful for analytics but should not be used as the sole mechanism for feature detection. Use feature detection (checking for specific browser APIs) instead.

What is user agent reduction?

Modern Chrome reduces its user agent string to limit fingerprinting. Specific OS versions and minor browser versions are replaced with generic values.

Can I test a user agent from a bot or crawler?

Yes. Paste any user agent string — including those from Googlebot, cURL, Postman, Puppeteer, or Playwright — and the tool will parse it.

Is my data sent to a server?

No. All parsing is performed locally in your browser using JavaScript string analysis.

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

The rendering engine processes HTML/CSS and executes JavaScript. Chrome, Edge, and Opera use Blink. Firefox uses Gecko. Safari uses WebKit.