Googlebot Will Start Supporting HTTP/2 Crawl for Some Sites From Nov 2020

Starting mid-November 2020, Googlebot will start crawling some sites over HTTP/2. They expect this change to make crawling more efficient in terms of server resource usage. With h2, Googlebot is able to open a single TCP connection to the server and efficiently transfer multiple files over it in parallel, instead of requiring multiple connections. The fewer connections open, the fewer resources the server and Googlebot have to spend on crawling. Server push is not yet enabled.

Googlebot decides which site to crawl over h2 based on whether the site supports h2, and whether the site and Googlebot would benefit from crawling over HTTP/2. If your server supports h2 and Googlebot already crawls a lot from your site, you may be already eligible for the connection upgrade, and you don’t have to do anything.

If you DON’T want Google to crawl and index using HTTP/2 you can do that by instructing the server to respond with a 421 HTTP status code when Googlebot attempts to crawl your site over h2 or you can send a message to the Googlebot team (this solution is temporary).

When a site becomes eligible for crawling over h2, the owners of that site registered in Search Console will get a message saying that some of the crawling traffic may be over h2 going forward. You can also look at your server logs to see if Googlebot is requesting content over HTTP/2.

If your server does not support HTTP/2  you don’t have to rush to enable it for SEO reasons, according to Google there’s no ranking or indexing benefit for crawling over h2, Googlebot will still continue to crawl over h1.