Free tool — runs in your browser

Which Google core update hit your site?

Drop your Search Console export and see every confirmed core update overlaid on your real traffic, with the impact of each one measured.

Your data is analyzed locally and never leaves your browser.

  1. 1. Open Search Console → Performance
  2. 2. Set the date range to “Last 16 months”
  3. 3. Export (top right) and download the zip

Know the moment the next core update starts

Two emails per core update: one when Google confirms it started and another when the rollout completes so you can rerun this analysis. No newsletter, unsubscribe anytime.

Want articles that survive core updates?

Sites that lose in core updates share a pattern: thin, unsourced content. ProofWrite writes articles the other way, with researched claims, cited sources, and trust signals baked in before you publish.

Start your free pilot

Wondering when the next one lands? See the live odds.

How it works

Your real data, Google’s real dates

Private by design

Your export is parsed and analyzed entirely in your browser. Nothing is uploaded. Analyzing a file makes zero network requests.

Official update history

Rollout windows come from Google’s own confirmed record of every core and spam update. It is the same live dataset behind our core update predictor.

A fair comparison

Fourteen clean days before each rollout against fourteen clean days after it, with rollout turbulence excluded. This is the comparison Google itself recommends waiting for.

Was it the core update, or something else?

Most “the update killed my site” diagnoses are wrong. Traffic drops have many causes: seasonality, a technical regression, a lost featured snippet, or a competitor publishing something better. The only way to attribute a drop to a core update is to line your daily data up against the confirmed rollout windows. That is the whole job of this tool: if your settled traffic stepped down right across a confirmed rollout and stayed stable elsewhere, the update is the likely cause. If the drop started two weeks before the rollout, it wasn’t the update, and the fix lives somewhere else.

The tool deliberately ignores the rollout days themselves. Mid-rollout rankings swing in both directions before settling. Google’s own guidance is to wait until a rollout is confirmed complete before assessing. Comparing settled traffic on both sides of the window is the honest measurement.

How to read your results

A single update with a clear loss tells you when your content was re-evaluated, and Google has been consistent about what core updates reward: expertise, first-hand experience, factual accuracy, and sources a reader can verify. A gain tells you the same thing from the other side. Several updates in a row trending the same direction is the strongest signal of all: it means each re-evaluation keeps reaching the same verdict about your content.

Treat “flat” results as genuinely good news after a rollout everyone else is complaining about. Stability through a core update means Google re-checked your niche and kept you where you were.

What to do about a confirmed hit

Recovery from a core update runs through content, not tricks. Google has said repeatedly that there is nothing to “fix” technically after a core update; the update re-weighed the quality of what you publish. The playbook that works is unglamorous: identify the pages that lost, strengthen them with real evidence and cited sources, remove or consolidate thin pages, and publish your strongest possible versions before the next update because recoveries typically become visible around subsequent core updates.

Knowing when that next window opens is the other half. Our core update predictor gives live odds for the next rollout, and the email alert above tells you the moment it starts, so the rebuild work lands while it can still count. And if the rebuild list is long, producing research-backed, source-cited articles at volume is exactly what ProofWrite automates.

Core update impact questions

How do I know if a Google core update hit my site?

Compare your settled traffic after the rollout completed with your traffic before it started — not the day-to-day swings during the rollout. This tool does exactly that from your own Search Console export: it averages the 14 clean days before each confirmed core update and the 14 clean days after its rollout finished, and reports the change. A drop that aligns with a confirmed rollout window, while other periods stay stable, is the classic signature of a core update hit.

How do I export my data from Google Search Console?

Open Search Console, go to the Performance report, set the date range to "Last 16 months", and click Export in the top right corner. Download the zip file and drop it into this tool as-is. It finds the daily date series inside automatically, whatever language your Search Console is in.

Is my Search Console data uploaded to your servers?

No. The file is parsed and analyzed entirely in your browser with JavaScript. Nothing is uploaded, stored, or sent anywhere. You can verify this from your browser’s network tab: analyzing a file makes no network requests. Only the confirmed core update dates come from our side, and those are public Google data.

Why does the tool say an update was "flat" when my traffic moved?

Daily search traffic naturally swings with weekdays, seasons, and news cycles. The tool reports movements under 5% as flat because changes that small are usually noise, not an algorithm update. It also excludes the rollout days themselves from the comparison, since rankings swing in both directions mid-rollout before settling.

What should I do if a core update reduced my traffic?

First, confirm the drop aligns with a confirmed update (that is what this tool shows) rather than seasonality or a technical issue. Then work on the content itself. Google has been consistent that core update losses reflect content quality re-evaluation: thin, unsourced pages lose to content with real evidence, expertise, and verifiable sources. Recovery typically becomes visible around subsequent core updates, which is why fixing content before the next one matters.

Which Google updates does the tool check against?

Every core update and every spam update Google has officially confirmed, sourced from the Search Status Dashboard — the same continuously refreshed dataset that powers our core update predictor. Spam updates are included because they have hit many sites as hard as core updates, and Google still confirms them separately (the June 2026 spam update being the most recent as of this writing). Spam updates are labeled in the chart and the table so you can tell the two apart.