---
title: http.user_agent · Cloudflare Ruleset Engine docs
description: The HTTP `User-Agent` request header, which contains a
  characteristic string to identify the client operating system and web browser.
chatbotDeprioritize: false
source_url:
  html: https://developers.cloudflare.com/ruleset-engine/rules-language/fields/reference/http.user_agent/
  md: https://developers.cloudflare.com/ruleset-engine/rules-language/fields/reference/http.user_agent/index.md
---

# http.user\_agent

`http.user_agent` String

The HTTP `User-Agent` request header, which contains a characteristic string to identify the client operating system and web browser.

Example value:

```txt
"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36"
```

Categories:

* Request
* Headers
