Google recently announced that its Googlebot (which indexes web pages) will start crawling some sites over HTTP/2 from November 2020.
HTTP/2 (aka h2) is the next major version of HTTP, the protocol the internet primarily uses for transferring data. It’s much more robust, efficient, and faster than its predecessor, due to its architecture and the features it implements for clients (for example, your browser) and servers.
(You can read more about HTTP/2 here.)
Googlebot decides which site to crawl over h2 based on whether the site supports h2 and if 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 your server still only talks HTTP/1.1, that’s also fine. There’s no explicit drawback for crawling over this protocol; crawling will remain the same, quality and quantity wise.
When a server is upgraded and 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 check in the server logs (for example, in the access.log file if the site runs on Apache).
The primary benefit of h2 is resource savings, both on the server side, and on Googlebot side. Whether Google crawls using h1 or h2 does not affect how a site is indexed, and hence it does not affect how much, or how fast Google plans to crawl from your site.
If you want more information about how we can help the management of your website’s indexing with Google and its SEO, please get in touch.