AWS is launching HTTP/2 support for CloudFront. You can enable it on a per-distribution basis today and your HTTP/2-aware clients and applications will start to make use of it right away. While HTTP/2 does not mandate the use of encryption, it turns out that all of the common web browsers require the use of HTTPS connections in conjunction with HTTP/2. Therefore, you may need to make some changes to your site or application in order to take full advantage of HTTP/2. Due to the (fairly clever) way in which HTTP/2 works, older clients remain compatible with web endpoints that do support it.
The connection from CloudFront back to your origin server is still made using HTTP/1. You don’t need to make any server-side changes in order to make your static or dynamic content accessible via HTTP/2.
Several AWS customers have already been testing CloudFront’s HTTP/2 support and have seen clear performance improvements. Marfeel is an ad tech platform that helps publishers to create, optimize, and monetize mobile web sites. They told us that CloudFront’s HTTP/2 support has reduced their first-render time by 17%. This allows the sites that they create to consistently load within 0.8 seconds. making them more accessible to mobile readers.