Delimiter.live
Network & Web Tools Runs in your browser Free · no account

User-Agent Parser

The user-agent parser breaks a browser user-agent string into the parts that matter: browser and version, rendering engine, operating system and device type. Paste any string from a log, or parse your own with one click.

Options
User-agent string 0 characters
Parsed user agent

Your result will appear here.

Not sure where to start? Use Load example.

Results update automatically and are calculated on your device. Nothing you type is sent to a server.

Runs in your browser. Processing happens entirely in your browser. Nothing you enter is sent to Delimiter.live.

How to use the User-Agent Parser

  1. Paste a user-agent string from a log file, or press the button to load your own.
  2. Read the parsed browser, engine, operating system and device type.
  3. Paste several strings, one per line, to parse a batch.

Example

Input
Mozilla/5.0 (iPhone; CPU iPhone OS 17_5 like Mac OS X) … Safari/604.1
Output
Browser: Safari 17.5
Engine: WebKit
OS: iOS 17.5
Device: Mobile

Common use cases

  • Working out which browser a bug report came from.
  • Summarising the platforms present in a server log.
  • Checking what your own browser reports before debugging a compatibility issue.

Limitations and things to watch for

  • User-agent strings are historically messy — almost every browser still begins with "Mozilla/5.0" for compatibility reasons dating back to the 1990s. Parsing is therefore pattern-based and can misidentify rare or deliberately disguised browsers.
  • Browsers are actively reducing the detail in user-agent strings for privacy, so modern versions report less than older ones. Feature detection is a better basis for decisions than user-agent parsing.
  • A user-agent string is supplied by the client and can be set to anything. Never rely on it for security.

Frequently asked questions

Why does every user agent start with "Mozilla/5.0"?
For historical compatibility. In the 1990s servers checked for "Mozilla" before sending modern HTML, so every browser added it. The convention stuck and is now meaningless.
Can I trust the user agent?
No. It is sent by the client and can be changed freely, by browser settings, extensions or any script. Treat it as a hint for analytics, never as a security or access control.
Does parsing happen on your server?
No. The string is parsed in your browser and nothing is transmitted.

Share this tool