User Agent Parser
Parse User-Agent strings to extract browser, OS, device, and engine details. Free online tool with instant results.
What is a User-Agent string?
A User-Agent string is an HTTP header sent by browsers to identify themselves to web servers. It contains information about the browser name, version, operating system, device type, and rendering engine.
How does a User-Agent parser work?
A User-Agent parser reads the raw UA string and uses pattern matching rules to extract structured data such as browser family and version, operating system name and version, device type (desktop, mobile, tablet), and the rendering engine used.
Why do different browsers have similar UA strings?
Most modern browsers are based on similar engines (Chromium/Blink) and include compatibility tokens in their UA strings to ensure websites serve them proper content, which makes them look similar.
Can User-Agent strings be spoofed?
Yes, User-Agent strings can be easily modified or spoofed. Browsers offer built-in or extension-based UA spoofing features, so UA-based detection should not be relied upon for security purposes.
What is UA-CH (User-Agent Client Hints)?
UA-CH is a modern replacement for the traditional User-Agent string. It provides structured, privacy-preserving headers that give servers only the specific information they need, reducing passive fingerprinting.
What information can be extracted from a User-Agent?
A User-Agent string typically reveals the browser name and version (e.g., Chrome 120), operating system (e.g., Windows 10, Android 14), device type (desktop, smartphone, tablet), and rendering engine (e.g., Blink, Gecko, WebKit).
Why is User-Agent detection important for web development?
User-Agent detection helps developers deliver optimized content for different devices, handle browser-specific quirks, implement progressive enhancement, and provide appropriate fallbacks for older browsers.
What are the limitations of User-Agent parsing?
UA strings can be spoofed, they may not accurately reflect actual browser capabilities, and the format varies across browsers. Modern web development increasingly relies on feature detection instead of UA sniffing.
How is User-Agent used in analytics?
Web analytics tools use User-Agent data to generate reports on visitor demographics, including browser market share, device usage trends, OS distribution, and mobile vs. desktop traffic ratios.
What is the difference between mobile and desktop User-Agent strings?
Mobile UA strings typically contain identifiers like 'Mobile', 'Android', or 'iPhone' and reference touch-capable devices, while desktop strings reference full operating systems like Windows, macOS, or Linux.
Can this tool parse any User-Agent string?
Yes, this tool can parse User-Agent strings from any browser, bot, crawler, or application. It handles standard browser UAs as well as less common ones from IoT devices, smart TVs, and specialized software.
Why are some User-Agent strings so long?
Long UA strings result from browsers including multiple compatibility tokens, engine version details, platform identifiers, and extension markers to maximize website compatibility.
How to Use User Agent Parser
Paste a User-Agent string to reveal the browser, engine, operating system, and device behind it, or analyze an entire list at once. Everything is computed locally in your browser and never sent anywhere.
- Paste a User-Agent string into the field with the placeholder '请输入需要解析的 User Agent 字符串...'.
- Press the '单条 UA 解析' (single UA parse) button to break the string into browser, OS, engine, and device details.
- Switch to the '批量解析与统计' (batch parse & stats) tab to process many strings together.
- Paste one User-Agent per line into the batch field whose placeholder reads '请输入批量 User Agent 列表，每行一个...'.
- Run the batch to get a result per line plus aggregate statistics across the whole list.
Deduplicate and sort your UA list before batch parsing — the statistics view then makes bot and crawler traffic obvious at a glance.
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