---
title: cf.tls_client_hello_length · Cloudflare Ruleset Engine docs
description: The length of the client hello message sent in a [TLS
  handshake](https://www.cloudflare.com/learning/ssl/what-happens-in-a-tls-handshake).
chatbotDeprioritize: false
source_url:
  html: https://developers.cloudflare.com/ruleset-engine/rules-language/fields/reference/cf.tls_client_hello_length/
  md: https://developers.cloudflare.com/ruleset-engine/rules-language/fields/reference/cf.tls_client_hello_length/index.md
---

# cf.tls\_client\_hello\_length

`cf.tls_client_hello_length` Number

The length of the client hello message sent in a [TLS handshake](https://www.cloudflare.com/learning/ssl/what-happens-in-a-tls-handshake).

Specifically, the length of the bytestring of the client hello.

Example value:

```txt
508
```

Categories:

* Request
* SSL/TLS
