Google algorithm updates, and where each one was confirmed

A three-day spam-detection improvement, and the most recent entry on Google's dashboard.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A three-day spam-detection improvement.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update running over about twelve days.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update that began two days after that month's spam update finished.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

The fastest rollout Google has recorded on its dashboard, finished in a single day.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

The first update Google logged specifically for Discover rather than for search results.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update running through the second half of December.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A spam update with an unusually long rollout of nearly four weeks.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update running over about two weeks.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update, the first of that year.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A spam update released a day after the December core update finished.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A second core update within six weeks of the November one, which is unusually close together.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update running over about three weeks.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

Not an update. A separate ranking fault Google logged while the August core update was rolling out.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A week-long spam-detection improvement.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

The last reviews update Google announced separately, before the system folded into its regular work.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update Google said used a different core system from the October one, which is unusual.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

Not an update. Google logged a ranking fault on its own dashboard and took most of the month to resolve it.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update that began while the October spam update was still running.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A spam update Google said targeted cloaking, scraping and auto-generated content, with a focus on several non-English languages.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A helpful content update that Google said improved its classifier, and which hit independent publishers noticeably hard.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update running over about two weeks.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

The reviews system widened again, and Google said it would stop announcing individual reviews updates after this one.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

The reviews system was extended past products to services and other kinds of review.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A link-spam system built on Google's own machine-learning model, aimed at cancelling the value of unnatural links rather than penalising sites.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

The helpful content system was extended beyond English to all languages.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A two-day spam-detection improvement.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A product reviews update running at the same time as that month's core update.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update that overlapped with a product reviews update, making the two hard to tell apart.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A product reviews update, the third in under a year.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update, the first of that year.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A product reviews update that Google said would reward reviews with evidence behind them.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

The page experience signals that had applied to phones since the previous summer were extended to desktop results.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

Another pass at review content, rewarding reviews that show real first-hand use.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A broad core update that landed in the middle of the holiday trading season, which Google was criticised for.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

A spam-detection improvement, and the first entry on the public dashboard Google now keeps.

Start and end dates are Google's own, published on its public status dashboard.

Google Search Status Dashboard source

Google changed how it writes the blue headline on a result, and started overriding the page's own title more often.

Google framed this as a change to how results are displayed, not a ranking update. It revised its own figures a few weeks later after complaints.

Google Search Central Blog source

Cancelled the ranking value of manipulative links at greater scale, alongside a reminder to tag affiliate, sponsored and guest-post links.

It ran about twice as long as Google first forecast.

Google Search Central Blog source

The second half of the split core update, carrying the changes held back in June.

Seobility reported by

A second same-day spam-detection change five days later, this one covering image results too.

Seobility reported by

A same-day improvement to Google's automatic spam detection in web results.

Seobility reported by

The first half of a core update Google deliberately split in two, because some of the changes were not ready.

Seobility reported by

Google unveiled a model it said was far more capable than BERT, trained across dozens of languages.

An announcement of a model, not a ranking change. The post is written entirely in future terms.

Google Blog source

Aimed at review content, favouring reviews with original testing and analysis over thin roundups.

Dates from industry trackers, which agree.

Google Search Central Blog source

A broad core update Google described as wide-reaching across languages and regions.

Dates cross-checked across four industry trackers.

Semrush reported by

A broad core update that took about two weeks and was one of the more disruptive of its era.

Dates cross-checked across four industry trackers.

Semrush reported by

A page lifted into the answer box stopped also appearing as a normal listing below it, so the box now uses up that page's slot.

Shipped silently. Google explained it only after site owners spotted it, and always called it a change rather than an update.

Search Engine Roundtable reported by

A short broad core update, reported as lower impact than the ones the year before.

Dates cross-checked across four industry trackers. Google published no completion notice.

Semrush reported by

A broad core update announced a few hours before release, and generally reported as milder than the June one.

No completion date was ever published.

Search Engine Roundtable reported by

Most result sets stopped showing more than two pages from the same site.

Google said explicitly this should not be thought of as an update, because it is not about ranking.

Search Engine Roundtable reported by

The first core update Google gave notice of before releasing it.

Search Engine Roundtable reported by

A broad core update the industry had already nicknamed Florida 2 before Google stepped in and named it after the month. That is where the month-and-year naming convention started.

Announced on Twitter. Google published no completion date.

Search Engine Roundtable reported by

Google described it as one of the broad core updates it runs a few times a year. Health, medical and money sites were hit hardest, which is where the nickname came from.

Medic is an industry nickname based on who lost, not a Google name.

Search Engine Land reported by

How fast a page loads became a ranking factor on phones. Google said it would only affect the very slowest pages.

Announced in January, rolled out in July.

Google Search Central Blog source

Google pulled result descriptions back to roughly their old length, a few months after lengthening them.

Google repeated that description length is decided per search, not by the page.

Search Engine Roundtable reported by

Another broad core adjustment in the same run as the March and August updates that year.

Date taken from an index listing rather than contemporaneous reporting.

Search Engine Land reported by

A broad core update aimed at how well pages matched what the searcher actually wanted, with no specific fix offered to sites that lost ground.

The date is Google's public confirmation. Tracking suggests the rollout began five days earlier. Brackets is an industry nickname.

Glenn Gabe, GSQI reported by

Sites built out of many near-identical keyword-variant pages reported losses across a few days in mid-December.

Google said it had shipped several minor routine improvements and explicitly denied there was a single named update.

Search Engine Journal reported by

Google changed how it builds the description under a result, and they got noticeably longer.

Google told site owners nothing about their meta descriptions needed to change. The widely repeated November date could not be verified.

Search Engine Roundtable reported by

Sites stuffed with low-value content built around ad revenue reported heavy losses.

Google never confirmed a named update. The name came from a joke by a Google engineer that every unnamed update be called Fred.

Search Engine Land reported by

Mobile pages that hide their content behind a pop-up you have to fight to close can rank lower.

Announced nearly five months ahead of the date it took effect.

Google Search Central Blog source

Google increased how much the mobile usability signal counted for.

Search Engine Journal reported by

An unnamed core quality update that Google staff confirmed on Twitter after site owners noticed the movement.

The date is the confirmation. The movement it explains began the preceding weekend.

Search Engine Roundtable reported by

A Panda refresh released deliberately slowly over months rather than all at once, after nearly a year with no refresh.

Sources give two different start days.

Search Engine Land reported by

Google changed how its core system weighs quality signals, and declined to say which ones.

Google confirmed the change but never accepted the name Phantom. Confirmation came about two weeks after the movement.

Search Engine Land reported by

Sharpened the copyright-notice signal enough to visibly push the worst infringing sites down.

Google's post said the change would go global the following week, so the visible effect came later.

Google Public Policy Blog source

A long-delayed Penguin refresh that let earlier casualties recover and caught newer link schemes.

Date taken from an index listing rather than contemporaneous reporting.

Search Engine Land reported by

The news module on the results page started pulling from ordinary sites, blogs and video rather than approved publishers only.

Confirmed by a Google spokesperson. No Google-stated launch day exists.

Search Engine Land reported by

A more precise Panda that Google said would let more good small and mid-sized sites through.

Search Engine Land reported by

Serving a site over an encrypted connection became a small positive signal.

Google said it carried less weight than content quality at the time. Two Google properties show different days.

Google Search Central Blog source

A third pass at the same spam-heavy search categories.

Search Engine Land reported by

A rewrite rather than a refresh, and it moved content-heavy sites a long way in both directions.

Search Engine Land reported by

Switched the target from spammy searches to the spammy sites themselves.

Google said only that it rolled out over a weekend, and sources give two different days.

Search Engine Land reported by

A refresh of the link-spam filter against the existing Penguin signals.

Date taken from an index listing rather than contemporaneous reporting.

Search Engine Land reported by

A rebuilt core engine that read the meaning of a whole question instead of matching the words in it one by one.

The date is the announcement. Google said it had already been live for about a month and never published an explainer.

Wikipedia reported by

A spam system aimed at the search categories where manipulation was worst, payday loans among them.

Search Engine Journal reported by

A deeper version of the link-spam system that reached past the home page into the rest of a site.

Date taken from an index listing rather than contemporaneous reporting.

Search Engine Land reported by

Stopped weak sites ranking on the strength of a domain name that happened to match the search term.

Announced by Google's webspam lead on Twitter rather than a Google blog. One source gives the previous day.

Search Engine Roundtable reported by

Started counting valid copyright removal notices against a site, pushing repeat infringers down.

Google announced the signal on this date and said it would take effect the following week. Pirate is an industry name.

Google Inside Search Blog source

A Panda refresh whose effects spread over several days instead of landing at once.

Single-source date.

Search Engine Journal reported by

A routine Panda data refresh.

Single-source date.

Search Engine Journal reported by

A Panda refresh Google described as small, though trackers recorded bigger movement than that.

Single-source date.

Search Engine Journal reported by

A Panda refresh that followed unusually soon after the last one, with little visible effect.

Single-source date.

Search Engine Journal reported by

A Panda refresh that landed days before Penguin, so the two are hard to separate in traffic records.

Single-source date.

Search Engine Journal reported by

A Panda refresh Google flagged on social media before it landed.

Single-source date.

Search Engine Journal reported by

A Panda refresh shipped alongside a batch of other quality changes.

Single-source date.

Search Engine Journal reported by

A Panda data refresh with no change to the algorithm behind it.

Single-source date.

Search Engine Journal reported by

Pushed a signed-in user's own Google+ content and their contacts' posts into the main results.

Personalisation feature, since retired with Google+.

Official Google Blog source

Demoted pages that buried the actual content under a screenful of advertising.

The Google post carries no day stamp, so this page records the month.

Google Webmaster Central Blog source

A small Panda refresh touching a narrow slice of searches.

Single-source date.

Search Engine Journal reported by

Got better at working out which searches want something recent, and showing newer pages for those.

Official Google Blog source

A Panda release that combined fresh data with changes to the signals feeding it.

Single-source date.

Search Engine Journal reported by

A Panda refresh that moved some well-known publishers unusually far in both directions.

Single-source date.

Search Engine Journal reported by

Rolled Panda out to most other languages, leaving Chinese, Japanese and Korean aside.

Single-source date.

Search Engine Journal reported by

A Panda refresh that reshuffled winners and losers without any disclosed change.

Single-source date.

Search Engine Journal reported by

A Panda refresh that Google suggested was better at spotting sites scraping other people's content.

Single-source date.

Search Engine Journal reported by

A Panda refresh with no announced change to the signals behind it.

Single-source date.

Search Engine Journal reported by

Took Panda beyond the United States to every English-language search.

One of a long run of Panda refreshes that rest on a single industry source.

Search Engine Journal reported by

Results started updating as you typed instead of waiting for you to press enter.

A change to the search interface, later withdrawn.

Official Google Blog source

Replaced the batch-rebuilt index with continuous indexing. Google said results came out around half as stale.

Official Google Blog source

Changed how Google judged relevance on long, specific searches, and thin pages that had been living off low-competition phrases lost their traffic.

Google confirmed it as a deliberate, lasting quality change but never named it. Rolled out over about a week.

Search Engine Roundtable reported by

Google opened a public sandbox so site owners could test a rebuilt indexing system before it went live.

The Google page confirms the month. The exact day comes from a secondary source.

Google Search Central Blog source

Put more weight on trust signals for short, broad searches, which in practice pushed big recognised brands up for generic terms.

Google confirmed the change existed and was internally called Vince, but denied it was a deliberate push for brands.

Search Engine Land reported by

A large reshuffle that was never explained. Some observers thought Google's own properties gained.

Google acknowledged movement in a webmaster forum but never named or described an update.

Search Engine Land reported by

Images, video, news, books and maps moved into the single list of results instead of sitting in separate tabs.

A change to what the results page shows, not to how pages are ranked.

Official Google Blog source

Plumbing, not ranking. It changed how Google picked a canonical URL, followed redirects and decided what to crawl.

Started in December and the switchover ran into March the following year.

Matt Cutts, then head of Google webspam reported by

A three-stage rollout that cut the value of reciprocal links, paid links and low-grade link networks.

Discussed by name by Google's webspam lead, but on his personal blog rather than a Google property. Rollout window is disputed.

Matt Cutts, then head of Google webspam reported by

Site owners reported a shake-up. Google said nothing had changed, and it is generally put down to a toolbar PageRank refresh.

Listed because every timeline carries it, but Google's position was that no update ran at all.

Wikipedia reported by

Changed which version of a duplicated or near-duplicated page Google chose to show.

A rollout over roughly three weeks, not a single day.

Search Engine Land reported by

Nobody ever worked out what it changed. Link quality and a holding pattern for new sites were the popular theories.

Community name, mechanism never established, no day-level date.

Wikipedia reported by

Widened the index and put much more weight on anchor text and on words that mean the same thing, rather than the exact phrase.

Community name. Dated to a few days in the second half of February.

Wikipedia reported by

Carried on where Florida stopped, stripping value from invisible text and stuffed meta tags.

Community name. Commonly dated around the third week of January.

Search Engine Land reported by

Retired the monthly rebuild in favour of refreshing part of the index every day, which ended the Google Dance for good.

Community name. No Google announcement and no day-level date.

Search Engine Land reported by

The last of the monthly index rebuilds that the industry called the Google Dance.

Community name. No Google announcement and no day-level date.

Wikipedia reported by

Changed how Google counted backlinks, and site owners noticed the crawler behaving differently at the same time.

Community name. No Google announcement and no day-level date.

Wikipedia reported by

Went after hidden text, hidden links, and sites that linked heavily to other sites under the same ownership.

Community name. No Google announcement and no day-level date.

Wikipedia reported by

The first Google update the industry bothered to name, after the search conference where it was discussed. It mixed a full index rebuild with ranking changes.

Community name. Google never announced it and no day-level date exists.

Wikipedia reported by