> For the complete documentation index, see [llms.txt](https://browsify.gitbook.io/browsify-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://browsify.gitbook.io/browsify-docs/understanding-key-terms/what-is-a-user-agent.md).

# What is a User Agent?

A **User Agent** is a string sent by a browser to identify itself (e.g., Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/123.0.0.0). **Browsify** uses this to detect and block bots or suspicious devices by analyzing their **User Agent** strings.