HTTP/2 to Origin

A protocol is a set of rules governing the exchange or transmission of data between devices. One of the most important protocols that run on the human-computer interaction layer, where applications can access the network services, is HTTP (Hypertext Transfer Protocol).

HTTP is a well established protocol that has several versions, and each version adds features that improve performance over the older one. HTTP/1.1 and HTTP/2 are widely deployed on the Internet today. HTTP/1.1 has been around for more than a decade, but in 2015 the IETF (Internet Engineering Task Force) introduced HTTP/2, which introduces several features to reduce page load times. To know more about the differences between HTTP/1.1 and HTTP/2, please refer to HTTP/2 versus HTTP/1.1 Open external link .

​​ Availability

​​ Disable HTTP/2 to Origin

At Cloudflare, HTTP/2 connection to the origin is enabled by default.

If you wish to disable HTTP/2 to Origin, you can follow these steps:

1. Log into the Cloudflare dashboard Open external link and select your account.
2. Choose the domain that will use HTTP/2 to Origin.
3. Select Speed > Optimization.
4. Navigate to the Protocol Optimization tab and under HTTP/2 to Origin set the toggle to Off.

​​ Protocol compatibility

Note that if the origin does not support HTTP/2, Cloudflare will initiate an HTTP/1.1 connection. We connect to servers who announce support of HTTP/2 connections via ALPN Open external link .

If you are unsure if your server supports HTTP/2, we suggest checking your origin server’s documentation or using a testing tool for HTTP/2 implementation (for example, h2spec Open external link ).