Googles John Mueller confirmed that Googlebot is not yet crawling over HTTP/3. He stated if you do implement HTTP/3 for your website, it does not suggest it wont benefit your users and therefore potentially your core web vitals metrics. Googlebot wont crawl over it yet.This came up on Twitter where Michael Kohlfürst asked John Müeller (not sure I did that right …) if Google is crawling over HTTP/3. The reality is, Google simply started crawling over HTTP/2 (if your website supports it) November 2020 and after that in May 2021 said over half of crawling is now done over HTTP/2. It is a bit early for HTTP/3 crawling, maybe?HTTP/ 3 is the 3rd and upcoming major variation of the Hypertext Transfer Protocol used to exchange information on the World Wide Web, along with HTTP/1.1 and HTTP/2. HTTP/3 runs over QUIC, which is published as RFC 9000. Since December 2021, the HTTP/3 procedure is still formally an Internet Draft, however is already supported by 73% of running web browsers, and according to W3Techs 24% of the top 10 million websites. It has been supported by Google Chrome (including Chrome for Android, and Microsoft Edge, which is based on it) because April 2020 and by Mozilla Firefox given that May 2021. Safari 14 (on macOS Big Sur and iOS 14) has actually likewise carried out the protocol but support is hidden behind a feature flag.Here are those tweets: I dont think we crawl with http/3 however that doesnt imply you wont see favorable effects for users (and with that, potentially indirectly core web vitals too).– & #x 1f9c0; John & #x 1f9c0; (@JohnMu) December 6, 2021 Theres constantly some risk, however it seems like the majority of the big players (CDNs, servers, customers) lag this, so Im not too anxious. It doesnt replace other connections, so even older gadgets will still work.– & #x 1f9c0; John & #x 1f9c0; (@JohnMu) December 7, 2021 So yes, if users connect with your website in a more responsive and quick way, that might make your users better and also might affect your CrUX data.Forum discussion at Twitter.

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