User Agent Parser

The User-Agent Parser is a client-side tool that extracts structured information from HTTP User-Agent strings. When you paste a User-Agent string (typically from a server log, analytics tool, or HTTP request header), the tool parses it using regex pattern matching to identify the operating system (Windows 10/11, macOS, Android, iOS, Linux), the browser (Edge, Chrome, Firefox, Safari), the browser version number, whether the client is mobile (detected by Mobi/Android/iPhone tokens), and whether it is a bot or crawler (detected by bot/crawl/spider keywords). The tool also shows your current browser's User-Agent string for comparison, making it easy to verify that parsing is correct by comparing a known string against the output. The results are displayed in a labeled, aligned format suitable for copying into reports or documentation.

User-Agent strings are the primary method for identifying client capabilities in server-side applications, analytics platforms, and CDN configurations. However, UA strings are notoriously complex — they are a historical accretion of browser vendor conventions, compatibility tokens, and version strings that resist simple parsing. The User-Agent Parser distills this complexity into a structured, human-readable summary. This is essential for debugging browser compatibility issues (confirming which browser and version a user is running), analyzing server log data (identifying the mix of browsers hitting your API), and verifying that analytics tools are correctly categorizing traffic.

This tool runs entirely in your browser — no data ever leaves your device. There is no server round-trip, no upload, no logging, and no account required. Your input is processed locally using client-side JavaScript and is never stored, transmitted, or accessible to anyone else. When you close the tab, everything disappears.

Why does my User-Agent show a different browser than expected?

<p>Some browsers include tokens from other browsers for compatibility (e.g., Chrome includes Safari/ in its UA string). The parser looks for the most specific token (Edg/, Chrome/, Firefox/) to determine the actual browser.</p>

Does this parse bot User-Agents accurately?

<p>The tool detects common bot keywords (bot, crawl, spider) but does not identify specific bots (Googlebot, Bingbot). For detailed bot identification, use a dedicated crawler detection library.</p>

Can I use this to detect ad blockers?

<p>No. Ad blocker detection requires checking for missing network requests or DOM elements, not User-Agent parsing.</p>

Why are User-Agent strings so complicated?

<p>User-Agent strings have accumulated tokens from decades of browser wars and compatibility requirements. Browsers include other browsers tokens for historical reasons (Chrome includes Safari/, Edge includes Chrome/). The parser looks for the most specific identifier to determine the actual browser.</p>

Can I detect the operating system version?

<p>The parser detects the OS family (Windows, macOS, Linux, Android, iOS) but not the specific version. For precise OS version detection, you would need to parse additional tokens like Windows NT 10.0 (Windows 10/11) or Mac OS X 10_15_7 (macOS Catalina).</p>

How accurate is bot detection?

<p>The tool uses simple keyword matching (bot, crawl, spider) which catches most common bots but may miss sophisticated ones that disguise their User-Agent as a regular browser. For comprehensive bot detection, use a dedicated service.</p>