HTTP/2 (originally named HTTP/2.0) is a major revision of the HTTP network protocol used by the World Wide Web. It was derived from the earlier experimental SPDY protocol, originally developed by Google. HTTP/2 was developed by the HTTP Working Group (also called httpbis, where "bis" means "second") of the Internet Engineering Task Force (IETF). HTTP/2 is the first new version of HTTP since HTTP 1.1, which was standardized in RFC 2068 in 1997. The Working Group presented HTTP/2 to the Internet Engineering Steering Group (IESG) for consideration as a Proposed Standard in December 2014, and IESG approved it to publish as Proposed Standard on February 17, 2015. The HTTP/2 specification was published as RFC 7540 on May 14, 2015.
Its proposed successor is HTTP/3, a major revision that builds on the concepts established by HTTP/2. Support for HTTP/3 was added to Chrome (Canary build) in September 2019 (and Cloudflare has also added support for it), and while HTTP/3 is not yet on by default in any browser, in 2020 HTTP/3 has non-default support in stable versions of Chrome and Firefox and can be enabled.