Improvements For Servers With HTTP/2
Many of the techniques mentioned above by developers placed additional strain on servers due to extra connections opened by browsers. These connection-related techniques are no longer necessary with HTTP/2. The result is lower bandwidth requirements, less network overhead and lower server memory usage.
On mobile phones, multiple TCP connections could cause issues with the mobile network, causing them to drop packets and resubmit requests. The additional requests just added to the server load.
HTTP/2 itself brings benefits for a server, as well. Fewer TCP connections are necessary, as stated above. HTTP/2 is easier to parse, more compact and less error-prone.
What HTTP/2 Means For SEOs
With GoogleBot adding support for HTTP/2, websites that support the protocol will likely see an additional rankings boost from speed. On top of that, with Chrome and Firefox only supporting HTTP/2 over HTTPS, many websites that have not yet upgraded to HTTPS may see an additional boost in rankings when they do.
I make this last statement with the caveat that many technical items have to be done correctly with HTTPS, or you will likely experience at least a temporary, if not permanent, drop when making the switch from HTTP.
The number one problem I see with sites switching to HTTPS is with redirects — not just 302s instead of 301s, but placement or writing of the redirects, additional hops or chains in the redirects and failing to clean up old redirects. There are many additional items that need to be cleaned up, such as internal links, external links where possible, mixed content, duplication issues, canonical tags, sitemaps, many tracking systems that need to be changed and more.
Let’s not forget what Gary Illyes said:
A final note, and an interesting thought from a conversation I had recently with Bill Hartzer at Internet Summit, is that Google may be pushing for HTTPS and only supporting HTTP/2 over HTTPS in Chrome because this will actually eliminate some of the competition from competing ad networks.
Bill said he couldn’t take credit for this idea, but it does make sense. A lot of the smaller networks don’t support HTTPS, so by recommending HTTPS and only supporting HTTP/2 over HTTPS, they are likely gaining more market share in the ad space.