You never know what’s going to happen when it comes to SEO, but 2021 stands out. Compared to 2020, we had more than 6 confirmed Google Updates and even more unconfirmed updates. Google also made some refinements to rankings and to how the SERPs (search engine result pages) work.
This post was updated December 30, 2021 because even more Google Updates occurred after it was first published!
“Summer of Updates”
Not only did we have the two back to back Core Updates in June and July, we got several Spam Updates, the Product Review Update, and the Page Experience rollout for Mobile for a busy 2021 “Summer of Updates”.
Per SEMrush, desktop results for January 2021 through October 2021 had 68% more high volatility days than in 2020. Mobile was even tumultuous with 84% more volatile days.

Google Search keeps evolving
2021 also saw Passages Ranking, the final phase of Mobile Indexing, and a change in how Google generates web titles.
The latter caused consternation among SEOs and a flurry of tweets showing examples of crappy web titles in the Google SERPs snippets. Below is an example where Google got it wrong even for its own web site.

Fortunately Google adjusted the system in September and it has been performing better.
Google 2021 Updates
So much happened in 2021, I found myself losing track. Accordingly, I created this post as a reference for myself and others.
- February – Passage Ranking
- March – Mobile Indexing for the whole Web
- April – Product Review Update
- June – June Core Update, Page Experience, and Spam Updates
- July – July Core Update, and Spam Updates
- August – Change in generated web titles
- October – Continuous scrolling
- November – Another Core and Spam Update
- December – Another Product Review Update and a Local Update too
(Literally as I am pushing the Publish button on this post on November 17th, there is another Core Update rolling out …)