HTTP/2 – ) 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.[1] HTTP/2[2] was developed by the Hypertext Transfer Protocol working group httpbis (where bis means “second”) of the Internet Engineering Task Force.[3] 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 IESG for consideration as a Proposed Standard in December 2014,[4][5] and IESG approved it to publish as Proposed Standard on February 17, 2015.[6][7] The HTTP/2 specification was published as RFC 7540 in May 2015.[8]

The standardization effort was supported by Chrome, Opera, Firefox,[9] Internet Explorer 11, Safari, Amazon Silk, and Edge browsers.[10] Most major browsers had added HTTP/2 support by the end of 2015.[11]

According to W3Techs, as of October 2018, 30.5% of the top 10 million websites supported HTTP/2.[12]