Is my User Agent string sent to any servers for parsing?

No. The User Agent Parser runs entirely inside your browser via local JavaScript. Your strings are never stored, logged, or uploaded to any remote API, ensuring absolute privacy.

Why do Chrome, Edge, and Opera user agents all include Safari and Mozilla?

Historically, early browsers (like Netscape/Mozilla and Safari) had features that web servers checked for. To avoid being blocked by servers that only recognized Netscape or Safari, newer browsers added those names to their User Agent strings to maintain backward compatibility. This is known as User Agent spoofing.

How does the Bot Detection feature work?

The parser checks the User Agent against a curated list of keywords and patterns used by search engines (like Googlebot, Bingbot, Baidu), social networks (Facebot, Twitterbot), and automated scripts (curl, wget, python). If a pattern matches, the parser flags the request as a bot/crawler.

What are Client Hints (UA-CH), and how do they relate to User Agent strings?

User Agent Client Hints are a modern alternative to the traditional User Agent string. They provide the same information (browser, OS, device) but in a more structured, secure, and privacy-conscious manner, reducing the risk of passive browser fingerprinting.

User Agent Parser - Parse User Agent String Online

What a User Agent String Contains

A user agent string is a line of text every browser sends with each web request, identifying the browser name and version, rendering engine, operating system, and sometimes CPU architecture and device type. A typical desktop Chrome string looks like Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36, which this parser breaks down field by field.

Why Chrome and Edge Both Mention Safari

Modern browsers keep older engine names like Mozilla, WebKit, and Safari inside their user agent string for backward compatibility, so websites that only check for those legacy tokens still serve the correct content. Chrome and Edge are both built on the Blink engine, itself a fork of WebKit, which is why their strings mention Safari even though neither browser is Safari itself.

How Bot Detection Works Here

This parser checks the submitted string against known signatures used by search engine crawlers such as Googlebot and Bingbot, social media link previewers, and automated scripts like curl or wget, flagging a match along with the detected bot name and category. Pasting a string like Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html) immediately flags it as a search engine crawler rather than a real browser session.

Why User Agent Client Hints Are Emerging

Because a full user agent string can be detailed enough to help fingerprint a specific device, browsers are shifting toward User Agent Client Hints (UA-CH), which expose the same browser, OS, and device category information through separate structured headers that a server must explicitly request. Use the Browser Info tool alongside this parser to compare the live values a browser reports against a pasted or historical user agent string.

User Agent Parser

Enter User Agent

Interactive Examples

Parser Results

Deep Dive: User Agent Parsing & Compatibility Testing

Understanding User Agent Strings

Browser Compatibility Testing

The Shift to User Agent Client Hints