Google Algorithm Update History

Where these dates come from

Only updates Google itself confirmed are on this page. Since November 2021 that means the Google Search Status Dashboard, which posts a start time when a ranking update begins and a second note when Google considers the rollout complete. For 2020 and 2021 the dates come from Google's own list of ranking updates on Search Central, which now redirects to the dashboard, so the source links point to an archived copy. For 2018 and 2019 they come from the Google SearchLiaison account on X and from Google's blogs.

Some early announcements only said an update went out "this week" or "last week". Those rows say Confirmed with the date of the announcement, because inventing an exact start day would be guessing. Updates the SEO community named and Google never confirmed, and unnamed volatility picked up by rank trackers, are left out on purpose. If you need to explain a drop to a client, a confirmed date with a source is worth more than a long list of maybes.

Types of Google updates

Ranking incidents are different. They are bugs that Google posts on the same dashboard, like the August 2024 issue that hit many results on the day a core update started. They are listed here in grey so you can rule them in or out when you look at a traffic chart.

How long a rollout takes

Across the 21 core updates where Google announced an end date, the median rollout was 14 days. The shortest took 3 days and the longest, March 2024, took 45. 8 of the 21 ran past the two weeks Google usually says it may take. Spam updates are faster, with a median of 7 days. Use the chart above for the type you care about. The practical point is simple: until the dashboard says the rollout is complete, the positions you see are not the final ones.

What to do when an update hits your site

This is the order I work in when a client's traffic drops and an update is on the calendar.

1. Check that the timing really matches. Open the Performance report in Search Console, set it to daily, and look for the day the drop starts. Then check your own change log. Migrations, a new theme, a robots.txt edit, broken redirects and accidental noindex tags cause more drops than updates do, and they often happen in the same weeks.
2. Wait until the rollout is complete, then a week more. That is also what Google recommends in its core updates guidance. Then compare a full week after the end date with a full week before the start date.
3. Rule out manual actions and security issues. Both have their own reports in Search Console. A manual action is a reviewer's decision, not an algorithm update, and it has its own fix and reconsideration request.
4. Find out what moved. Compare pages and queries for the two periods. A loss across the whole site points to a site-wide assessment. A loss on one section or one kind of page, like thin category pages or old news posts, points at that content. Check Web, Images and News separately, and Discover if you get traffic from it.
5. Match the fix to the update type. After a core update, look at the pages that now rank for your lost queries and be honest about what they do better. After a spam update, read the spam policies and remove whatever practice you recognise. A small move, like position 2 to 4, usually needs no action at all.
6. Make changes you would make anyway for readers. Merge or improve thin pages, add the first-hand detail only you have, fix pages that answer a different question than the one people search. Avoid quick fixes like changing publish dates, rewriting every title, or deleting sections in bulk without data.
7. Write down the date of every change you make. Recovery is slow. Google says it can take several months for its systems to recognise improvements, sometimes not until the next core update, so you need the dates to read the result later.

Core update or spam update: reading the drop

A core update is a reassessment, not a penalty. Pages that fall have not necessarily done anything wrong; other pages may simply serve the search better now, and Google's advice is to assess the site as a whole with its self-assessment questions on helpful, reliable, people-first content. A spam update is closer to enforcement: it targets practices named in the spam policies, and the fix is to stop the practice. Link spam is the hard case. Google's documentation says that once its systems remove the effect of spammy links, any ranking benefit those links gave cannot be regained, so a disavow file will not bring the old positions back. The way forward is earning links that do not need to be hidden.

How to use this tool

Filter by type to compare, for example, every core update against every spam update. Pick a year to see how crowded it was: 2021 and 2022 each had 10 confirmed updates and 2023 had 9 plus a ranking incident, with updates overlapping, which makes it hard to say which one moved a site. The search box matches names and types. Every row links to its official source, and you can download the filtered list as CSV to line it up against your own Search Console export or annotate an analytics chart.