User Agent

What Is a User Agent?

A user agent is a string of text that your browser sends to every website you visit. It identifies the browser type, version, operating system, and sometimes the device. Websites use this information to serve appropriate content — like showing a mobile version of a site to smartphone users.

What Does Your User Agent Reveal?

A typical user agent string contains:

• Browser name and version — e.g., Chrome 120, Firefox 121, Safari 17
• Operating system — e.g., Windows 10, macOS 14, Android 14, iOS 17
• Rendering engine — e.g., Blink, Gecko, WebKit
• Device type hints — some user agents indicate mobile or tablet devices

This information helps websites optimize their layout and functionality for your specific browser and device combination.

User-Agent Limitations

User agents are becoming less reliable as a source of accurate browser information. Modern browsers may report simplified user agents to prevent fingerprinting, and some browsers allow users to customize their user agent string entirely. The information shown in user agent strings is self-reported by the browser and may not always be accurate.

Privacy Considerations

Your user agent is shared with every website you visit and contributes to your browser fingerprint. While you can modify it using browser extensions or settings, doing so may occasionally break website functionality. Some privacy-focused browsers automatically simplify user agent strings to reduce fingerprinting without breaking sites.