When did Google officially make speed a ranking factor?

Google officially made load speed a ranking factor:

• in 2010 - for desktop search. Back then the company announced that it takes page load time into account in the overall ranking algorithm.
• in July 2018 - for mobile search, as part of an update called the Speed Update.

Since 2021 the importance of speed has grown even more: Google introduced the Core Web Vitals metrics (LCP, FID/INP, CLS) and included them in the so-called Page Experience Update, an update that evaluates the overall "interaction experience" with a site.

So today speed is not just a technical parameter, but part of the official page-quality assessment algorithm.