How to tell which Google update hit your site: a 5-step method

A traffic drop has one start date, and Google publishes the start and end dates of every ranking update it confirms. Matching the two is most of the work. The rest is ruling out everything else that can move a line in Search Console on the same day: manual actions, a second update rolling out at the same time, seasonal demand and changes you made to your own site.

Which Google updates could have caused the drop?#

Only confirmed updates can be matched to a date. Google records each one on the Search Status Dashboard ranking history, with its start date and duration. Our Google Algorithm Updates timeline holds the same record for every update since November 2021: 40 Google-confirmed updates, 39 of them completed, with the full list downloadable as CSV.

Rollouts are not single days. The durations below are Google’s own, from the Search Status Dashboard history. Across the 39 completed updates the median rollout ran 14 days. Core updates, 16 of them, had a median of 14.5 days and ranged from 6 days 4 hours to 45 days. Spam updates, 10 of them, had a median of about 7 days and ranged from 19 hours 30 minutes to 26 days 15 hours. Helpful content updates (3) had a median of 15 days, product reviews updates (5) a median of 14 days, and there were 2 reviews updates. A drop that starts ten days after an update began can still belong to it, if the rollout was still running.

The quickest way to test the dates is the Google algorithm update checker: upload the Dates.csv file from a Search Console Performance export and it shades every confirmed update over your daily clicks, with a week-before and week-after comparison for each.

How do you line up a Search Console drop with update dates?#

Start in the Performance report of Search Console. Google’s guide to debugging traffic drops recommends setting the date range to the last 16 months, which shows the drop against a full year of your own pattern. Then:

1. Find the first day of a sustained drop, not the lowest day. The start date is what you match.
2. Check that date against the dashboard’s start and end dates for each update. A drop that begins before an update started cannot be that update.
3. Wait for the rollout to finish. Google’s core update guidance recommends “waiting at least a full week after a core update completes before analyzing your site in Search Console.”
4. Compare a 7-day window after the rollout with a 7-day window before the update began, not with the rollout window itself, which is still moving.

Seven-day windows matter because search traffic has a weekday cycle. Many sites see different volumes on weekdays and weekends, so comparing one Tuesday with one Saturday can invent a drop. Two whole weeks each contain every day of the week once, and the cycle cancels out.

Did the drop happen in web, image, video or news search?#

Google’s core update guidance is direct: “Analyze different search types separately.” It helps show whether a drop happened in Web Search, Google Images, Video mode or the News tab. Use the Search type filter at the top of the Performance report and check each one. A drop confined to one surface narrows the cause; a drop across all of them at once points to something site-wide.

Is it a manual action rather than an algorithm update?#

Check this before blaming any update. Google’s spam policies state that violations are detected “through automated systems and, as needed, human review that can result in a manual action.” A manual action is not silent: Google says it will notify you “in the Manual actions report and in the Search Console message center.” Its debugging guide gives the same instruction: check the Manual Actions report to see if any have been issued. An empty report rules this cause out.

Was it a core update or a spam update?#

The two ask different things of you. Google describes core updates as “significant, broad changes to our search algorithms and systems,” not a verdict on one practice. Spam updates improve its automated spam detection, and Google’s advice for a site that moves after one is to “review our spam policies” for compliance. If you can name a practice on your site that a spam policy describes, a spam update is the likelier cause; if you cannot, look at the core update.

What if two updates overlapped?#

Then the dates cannot separate them. In our record, 10 of the 39 completed updates overlapped another update’s rollout, in 5 pairs:

• March 2024 core update and March 2024 spam update
• November 2023 core update and the November 2023 reviews update
• October 2023 core update and October 2023 spam update
• December 2022 helpful content update and December 2022 link spam update
• September 2022 core update and September 2022 product reviews update

A drop inside one of these windows needs the core or spam test above, and the honest answer may be that both updates were live and either could be responsible.

Could it be seasonality or a change on your own site?#

Google’s debugging guide lists causes other than updates: technical issues, security issues, site moves and migrations, and seasonality and changing interests. The 16-month view shows whether the same drop happened at the same time last year. For demand, Google suggests checking top queries on Google Trends to see whether a drop is only yours or across the web. Then check your own change log: a redesign, a migration, a robots.txt edit or a template change on the drop date explains it more simply than an update.

Once you know which update it was, what next?#

If the evidence points to a core update, Google’s recovery guidance is specific: wait, compare, judge the size of the drop and self-assess rather than reach for quick fixes. We cover it step by step in what to do after a Google core update. If it points to a spam update, start from Google’s spam policies and the practice you identified.