A Google algorithm update is a change to the systems that rank search results, and it can move a page up or down the rankings without anything on that page having changed.
Before you touch the site, work out which event actually happened. A core update, a spam update, a manual action and a technical fault produce the same symptom, falling traffic, and each one is handled differently. The start and end dates of every announced update sit on a single page, Google's Search Status Dashboard, and that is where any diagnosis starts.
Google changes its algorithm thousands of times a year, and rarely says so
In 2023 Google launched 4,781 changes to Search, after 719,326 quality tests run by Search Quality Raters, 16,871 live traffic experiments and 124,942 side-by-side comparisons. The figures are Google's own, from its page on how changes to Search are tested. That works out at about thirteen launches a day.
Of those thousands of changes, Google announces around ten a year: the ones that get a name and a line on the dashboard. Everything else ships without notice, which is why rankings move even in weeks when officially nothing is happening. Sistrix keeps a list of known updates, confirmed and unconfirmed, going back to 2002.
The named updates (Panda in 2011 on low-quality content, Penguin in 2012 on manipulative links, Hummingbird in 2013 on the semantic understanding of queries) have been absorbed into the core algorithm and no longer run as separate filters. If you want to know what happens upstream, the steps that take a page from crawling to ranking are covered in how search engines work.
Core update, spam update and manual action are not the same thing
All three show up in the same traffic graph, but their causes and fixes are opposite. The difference that matters: a core update is not a verdict on your site. Google's documentation on core updates says a page that loses positions after one does not necessarily have anything wrong with it: other pages may simply have been judged more relevant. A manual action, on the other hand, is exactly a verdict, made by a person, and it comes with a notification.
| Core update | Spam update | Manual action | |
|---|---|---|---|
| What it is | A broad reweighting of the ranking systems | Action by the automated spam-fighting systems | Human review of a policy violation |
| Where you see it | Search Status Dashboard | Search Status Dashboard | Manual actions report in Search Console |
| Does it concern you? | Not necessarily: it affects the web, not your site | Yes, if you use a prohibited practice | Yes, always: you have been notified |
| Duration | 6 to 45 days for core updates since 2024 | 19 hours to 26 days | Until you submit a reconsideration request |
| What to do | Assess the whole site, not individual pages | Remove the practice and wait for reprocessing | Fix it, then request reconsideration |
The fourth case is a technical fault, which has nothing to do with updates and can be recognised by the shape of the drop: everything falls on a single day, across all queries at once. Which faults wipe out traffic, and the symptom each one leaves, is the first chapter of technical SEO.
How long a roll-out really lasts
An update is not a switch. Google rolls it out over days or weeks and, until it has finished, Search Console data tells you nothing stable. These are the official durations of the core updates since 2024, taken from the dashboard (US/Pacific time).
| Core update | Start | Roll-out duration |
|---|---|---|
| March 2024 | 5 March 2024 | 45 days |
| August 2024 | 15 August 2024 | 19 days 4 hours |
| November 2024 | 11 November 2024 | 23 days 13 hours |
| December 2024 | 12 December 2024 | 6 days 4 hours |
| March 2025 | 13 March 2025 | 13 days 21 hours |
| June 2025 | 30 June 2025 | 16 days 18 hours |
| December 2025 | 11 December 2025 | 18 days 2 hours |
| March 2026 | 27 March 2026 | 12 days 4 hours |
| May 2026 | 21 May 2026 | 11 days 21 hours |
The duration column holds the most useful information in the table: core updates have become shorter. The March 2024 update took 45 days, the last two less than two weeks. The window in which it pays to sit still has dropped from six weeks to about three, including the wait Google asks for after completion.
Spam updates follow a different, less predictable rhythm: the August 2026 one lasted 2 days 16 hours, the June 2026 one just over two days, while the August 2025 update ran for 26 days 15 hours. The practices these updates target are listed in the spam policies, which Google revises on its own schedule: the latest revision, on 2 September 2026, added back button hijacking. The classics, from keyword stuffing down, have been there for twenty years.
Google's protocol, with the thresholds most summaries leave out
Google's page on core updates contains a procedure with precise numbers. It is the part that saves the most wasted work, and it is often skipped. In order:
- Check on the dashboard that the roll-out has finished, and note the start and end dates.
- Wait at least a full week after completion before opening Search Console.
- Compare that week with a week before the update started. Not day against day.
- Look at how far the position dropped. From 2 to 4 is a small drop and Google advises against intervening. From 4 to 29 across a wide range of queries is a significant drop, and calls for an assessment of the site as a whole.
- Separate the search types (Web, Image, Video, News): a drop concentrated in just one has other causes.
- Widen the date range to 16 months, the Search Console maximum, to rule out seasonality.
Step 4 is the one most often skipped. Below the small-drop threshold, the official advice is to avoid radical changes to pages that already perform well: the risk is breaking something that worked. The full order for isolating the cause of a drop, update or not, is in website traffic drop.
What not to do in the weeks after an update
On this Google is unusually explicit. No "quick fix" changes, like removing a page element "because you heard it was bad for SEO". Deleting content is a last resort, to be considered only if you think it can't be salvaged. And the real timescales have to be accepted: some changes take effect in a few days, others need several months before the systems recognise that the site as a whole has changed.
You don't have to wait for the next core update to see an improvement, though. Google says it updates its algorithms continually, including smaller core updates that aren't announced because they aren't widely noticeable, and that is where improvements get picked up first.
The self-assessment Google asks for covers the whole site, not just the pages that lost positions, and it works better when done by someone who didn't write those pages. The questions are about first-hand experience, expertise and trustworthiness: we have collected them in E-E-A-T. It is also where an SEO programme starts when a site comes to us with a broad, persistent drop.
On timescales it is worth being honest. In the Macropix project the Italian keyword "monitor pubblicitario" (advertising display) went from position 88 in 2020 to position 2 in 2025, according to Semrush, and the five years are not a detail: they measure how slowly rankings move when content work is what moves them. The full figures are in the manufacturing case study.
Where to check whether an update is under way
There is one official source, the Search Status Dashboard, which also publishes an RSS feed and its history in JSON: you can monitor it without opening it by hand. In Search Console, the Data anomalies page flags a different case, when the drop comes from a logging error or a change in how data is processed. That is a measurement problem, not a ranking one, and it should be ruled out before anything else.
Third-party tools measure something else again: SERP volatility. The Sistrix Google Update Radar compares today's fluctuations with the average of the last three months, Semrush Sensor scores daily volatility by category, and Search Engine Roundtable gathers reports before Google confirms anything. They don't tell you the cause, they tell you whether the movement is yours or everyone's. When the drop is yours alone and the dashboard is empty, the update is not the reason. For seasonality, the quick check is Google Trends: if demand has fallen for everyone, you haven't lost positions, people have stopped searching.
Something rarely said: after a core update the useful question is not "what did I break" but "who overtook me, and on which queries". Position is relative. If you drop from 3 to 6 without touching anything, three pages have moved ahead of you, and reading those three tells you more than any audit of your own site. It also separates two situations that are handled in opposite ways. If the pages ahead of you use a different format from yours, a video, a comparison, a page with prices, the problem is content and can be tackled in a few weeks. If they are the same formats on bigger domains, the problem is authority, the ranking factors to work on are different, and the timescale is the five years mentioned above.
Frequently asked questions about Google algorithm updates
In 2023 Google launched 4,781 changes to Search, about thirteen a day, after more than 719,000 quality tests. It announces around ten of them a year: the ones that get a name on the Search Status Dashboard, meaning core updates, spam updates and changes to individual features.
Compare the date of the drop in Search Console with the dates on the Search Status Dashboard. If they don't match, the update is probably not the cause: check technical problems, the Manual actions report, the Data anomalies page and seasonality on Google Trends first.
No. Google says that a drop after a core update does not necessarily mean there is anything wrong with your content, because these updates don't target specific sites. The real penalty is a manual action, which comes from a human review and is notified in Search Console.
According to Google some changes take effect in a few days, others need several months, because the systems have to recognise that the site as a whole produces helpful content over the long term. You don't need to wait for the next core update: smaller, unannounced updates pick up improvements sooner.
No. Until the roll-out has finished the data isn't stable, and Google advises waiting at least a full week after completion before analysing Search Console. If the drop is small, for example from position 2 to 4, the advice is to leave pages that already perform well alone.
