HTTP/2 is the latest version of HTTP. HTTP/2 enables more secure and efficient access to resources. This topic describes the concept and benefits of HTTP/2. This topic also describes how to enable HTTP/2.


An HTTPS certificate is configured. For more information, see Configure an SSL certificate.
  • If you are configuring an HTTPS certificate for the first time, you must wait for the certificate to take effect before you enable HTTP/2.
  • If you disable HTTPS certificates after your enable HTTP/2, HTTP/2 is automatically disabled.

Background information

HTTP/2, originally named HTTP 2.0, is the latest version of HTTP. It is supported by all major browsers such as Google Chrome, Internet Explorer 11, Safari, and Mozilla Firefox. HTTP/2 provides optimized performance and is compatible with HTTP/1.1 semantics. HTTP/2 is similar to SPDY but differs greatly from HTTP/1.1.

Benefits of HTTP/2:
  • Binary encoding: Unlike HTTP 1.x that parses data into texts, HTTP/2 splits the data to be transmitted into messages and frames and encodes them into binary formats. Binary encoding makes HTTP/2 more scalable. For example, frames can be introduced to transmit data and instructions.
  • Content security: HTTP/2 is designed based on HTTPS, protecting content security while maintaining network performance.
  • Multiplexing: HTTP/2 allows multiplexing of multiple concurrent streams on a single connection. Specifically, you can initiate countless requests at the same time over one connection by using a browser, and the server returns the responses to these requests at the same time. In addition, you can set stream dependencies, which the client uses to inform the server of the importance of a given stream relative to other streams on the same connection, so that resources can be allocated appropriately.
  • Header compression: HTTP headers carry large volumes of information, which is transmitted repeatedly. HTTP/2 compresses HTTP headers into the HPACK format, allowing both ends of the communications to each cache a copy of the HTTP header indexes and hence transmit only index numbers for duplicate HTTP headers. This increases transmission speed and efficiency.


  1. Log on to the DCDN console.
  2. In the left-side navigation pane, click Domain Names.
  3. On the Domain Names page, find the domain name that you want to manage, and click Configure in the Actions column.
  4. In the left-side navigation pane on the details page of the specified domain, click HTTPS Settings.
  5. In the HTTP/2 Setting section, turn on HTTP/2.
    Enable HTTP/2