Free User Agent Parser — Decode Browser, OS & Device Information Instantly

0 of 0 ratings

What Is a User Agent Parser?

A user agent parser is a tool that decodes the user agent string — a line of text your browser sends to every website you visit. This string contains information about your browser name and version, operating system, device type, and rendering engine. While user agent strings are notoriously complex and hard to read, our parser breaks them down into clear, human-readable details.

Simply paste any user agent string into our free tool to instantly identify the browser, OS, device type, and whether it's a bot or a real user.

Why User Agent Parsing Matters

Understanding user agent strings is essential for web developers, SEO professionals, and security analysts:

  • Browser Compatibility — Identify which browsers and versions your visitors use to ensure your site renders correctly
  • Device Detection — Determine if visitors are on mobile, tablet, or desktop to optimize responsive design
  • Bot Identification — Distinguish search engine crawlers (Googlebot, Bingbot) from real users and malicious bots
  • Analytics Verification — Cross-check traffic data and verify suspicious visits in your server logs
  • Content Negotiation — Serve different content or formats based on the client's capabilities
  • Security Monitoring — Detect unusual or spoofed user agents that may indicate scraping or attacks

Anatomy of a User Agent String

A typical user agent string looks like this:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

This tells us:

  • Browser: Chrome 120
  • Operating System: Windows 10 (64-bit)
  • Engine: Blink (via AppleWebKit/537.36)
  • Device: Desktop

The "Mozilla/5.0" prefix and "Safari/537.36" suffix are historical artifacts — nearly all modern browsers include them for compatibility reasons.

How to Use the User Agent Parser

  1. Paste a user agent string into the input field — or leave it empty to detect your own browser's user agent
  2. Click Submit to parse the string
  3. View the decoded results: browser name, version, OS, device type, and engine
  4. Use the information for debugging, analytics, or security analysis

Common Use Cases

  • Analyzing server logs — Parse user agents from access logs to understand your traffic composition
  • Debugging rendering issues — Identify the exact browser and version causing display problems
  • Detecting Googlebot — Verify if a crawler is genuinely from Google or a spoofed bot
  • Mobile optimization — Check if your site correctly detects mobile user agents
  • A/B testing — Segment visitors by browser or device for targeted experiments

Common Search Engine Bot User Agents

  • Googlebot: Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)
  • Bingbot: Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)
  • Googlebot Smartphone: Includes "Mobile" in the string for mobile-first indexing
  • Yandex: Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)

Related Tools

Frequently Asked Questions

What is a user agent string?

A user agent string is a text identifier sent by your browser (or any HTTP client) with every web request. It tells the server what browser, operating system, and device you're using. Servers can use this information to deliver optimized content, track analytics, or enforce access rules.

Can user agent strings be spoofed?

Yes — user agent strings can easily be modified or faked. Browser extensions, developer tools, and HTTP clients like cURL let you set any user agent you want. This is why server-side security should never rely solely on user agent verification.

Why do all browsers say "Mozilla" in their user agent?

This is a historical quirk. In the early web, servers would send advanced content only to Mozilla (Netscape) browsers. When Internet Explorer and later browsers appeared, they added "Mozilla/" to their user agent strings to ensure they received the same content. The practice stuck, and today virtually all browsers include it.

How do I find my user agent?

Simply visit this page — the tool can automatically detect and display your current browser's user agent string. Alternatively, you can open your browser's developer tools (F12), go to the Console tab, and type navigator.userAgent.

Share

Popular tools