Google March 2025 Core Update

Google’s March 2025 core update began rolling out on 13 March 2025 and completed on 27 March 2025, a 14-day rollout. It was the first broad core update of 2025 and took roughly a week longer than the December 2024 update, which finished in about six days.

The longer rollout did not translate into larger effects. Every tracking provider that reported on it measured volatility close to December’s, and SISTRIX found no major movers among the top 100 domains at all.

What the tracking tools measured

Semrush. Mordy Oberstein described the March and December 2024 updates as “similar in size” on volatility. Measured against baseline ranking volatility rather than against each other, the two updates sat within very similar ranges, with what Oberstein called “a mere .1 difference between the two”. Broken down by vertical, health showed a noticeably larger change than the other sectors.

Similarweb. Darrel Mordechai told Search Engine Land the update “was not the most volatile core update” the company had seen, and showed “similar levels of volatility” to December. Similarweb’s breakdown found slightly lower fluctuation in the top three positions than December produced, but more movement across the top five. Finance fluctuated most, particularly in the top five. Travel was notably stable in the top three.

SISTRIX. Visibility changes only became legible in the data from 16 March, three days after the announcement. SISTRIX’s summary was that absolute changes across all SERPs were relatively low, with no major rising or falling domains in the top 100.

One practical caveat from the rollout: several rank-tracking tools were disrupted by unrelated changes Google made to the search results page during the same window, which muddied third-party readings. Search Console remains the cleaner record for any individual site.

How this update looked in hindsight

Semrush revisited the comparison after the June 2025 core update. Plotting the two updates against each other, Oberstein found that March’s initial burst of volatility was slightly more severe than June’s, and that “for a moment in time, the March update was more powerful”.

His conclusion was still that June was the larger event. On the churn measure, the share of post-update top-ten URLs that had not ranked in the top twenty beforehand, June came in 72.4% above March. March produced the sharper spike; June produced the more durable reordering.

Which UK domains moved

SISTRIX published a hand-picked list of affected domains, selected by growth profile rather than ranked by size of movement. It illustrates the shape of the update rather than serving as a leaderboard. Figures are SISTRIX visibility index points, a score derived from a domain’s rankings across a fixed keyword set, so changes are relative to that domain’s own baseline rather than a traffic estimate.

The largest UK declines in that sample:

• quora.com 188.26 to 145.99 (-42.27, a 22% drop)
• vocabulary.com 184.66 to 155.24 (-29.42, 16%)
• expedia.co.uk 66.07 to 47.83 (-18.24, 28%)
• last.fm 68.07 to 50.50 (-17.57, 26%)
• medicalnewstoday.com 136.65 to 120.89 (-15.76, 12%)

The largest UK gains:

• company-information.service.gov.uk 329.30 to 380.87 (+51.57, 16%)
• thesaurus.com 107.01 to 152.34 (+45.33, 42%)
• therange.co.uk 62.22 to 75.31 (+13.09, 21%)
• patient.info 20.27 to 32.53 (+12.26, 61%)
• asos.com 79.30 to 89.55 (+10.25, 13%)

Patterns in the data

Health moved in both directions. Semrush recorded health as the sector with the biggest volatility change, which is easy to read as “health was hit”. The SISTRIX sample does not support that reading. Medical News Today fell 12%, cancer.gov 23% and yalemedicine.org 32%, while patient.info rose 61%, americanpregnancy.org 91% and urologyhealth.org 95%. The sector was reshuffled rather than demoted.

Reference sites split. Thesaurus.com gained 42% and the Longman dictionary site ldoceonline.com gained 53%, while vocabulary.com lost 16% and Urban Dictionary lost 29%. Sites answering near-identical queries moved in opposite directions.

The losers were not thin sites. Quora, Expedia, Amazon, Medical News Today, Harvard Business Review, HMRC and cancer.gov are established, well-resourced domains, not thin or affiliate-led ones.

The large percentages come off small bases. Several domains in the SISTRIX sample posted gains above 90%, but from visibility bases under 1.0 point. A move from 0.52 to 1.49 is real, and it is also within the range ordinary week-to-week noise produces.

What this means

There is no specific action to take in response to this particular update, and Google said as much at the time: “There’s nothing new or special that creators need to do for this update as long as they’ve been making satisfying content meant for people.”

A site that moved sharply during a fortnight when three independent providers measured ordinary volatility and no large movers in the top 100 has probably not been fully explained by the update alone. Search Console will show whether the movement tracks the rollout dates.

Google’s core update guidance asks whether content would be recognised as authoritative by someone with genuine expertise in the field. Disavowing links, changing URLs and other technical responses do not address what a core update adjusts.

Tracking the update

• Started: 13 March 2025
• Completed: 27 March 2025
• Duration: 14 days
• Type: Broad core
• Confirmed by: Google Search Status Dashboard

Sources

• Data providers: Google March 2025 core update had similar volatility to the previous update — Search Engine Land
• Google Core Update March 2025 — SISTRIX
• Google Search Status Dashboard — Ranking Updates
• Google Search Central — Core Update Recovery