This is a detailed document describing HTTP/2 (RFC 7540), the background, concepts, protocol and something about existing implementations and what the future might hold.

The contents are translated into several different languages.

See for the canonical home for this project.

See for the source code of all book contents.


The document is distributed under the Creative Commons Attribution 4.0 license:


I encourage and welcome help and contributions from anyone who may have improvements to offer. We accept pull requests, but you can also just file issues or send email to with your suggestions!

/ Daniel Stenberg

Last updated