Why does Google Ads show more conversions than GA4?
Google Ads only counts sales that followed its own ads, dated to the click, and may include modeled conversions. GA4 shares each sale across every channel and dates it to the purchase. Counting settings and time zones widen the gap.
By Joris van Huët, Founder & CEOUpdated 6 min read
Run the numbers for your store: the free break-even ROAS calculator.
Google Ads usually shows more because it only looks at its own ads. If a buyer clicked your ad and later bought through email or organic search, Google Ads still counts the sale. GA4 shares the credit, or gives it all to the channel that closed. Google Ads also dates sales to the click and can include modeled conversions.
What one store's data shows
The usual answer is a settings checklist: windows, counting, view-throughs. Those matter, and the checks at the end cover them. Here is what one store's GA4 export adds about where the gap lives.
One store's anonymised GA4 export, 1 January 2024 to 21 August 2026. It holds shares of revenue only: no ad spend, no order counts.
| What the export shows | Share of revenue | Source cell |
|---|---|---|
| Journeys with 1 touch (0.5 days to buy) | 79.5% | Journeys sheet, 1 touch row |
| Journeys with two or three touches (12.5 days to buy) | 12.2% | Journeys sheet, two to three touches row |
| Journeys with four to nine touches (16.9 days to buy) | 5.4% | Journeys sheet, four to nine touches row |
| Journeys with ten or more touches (16.0 days to buy) | 3.0% | Journeys sheet, ten or more touches row |
On the Journeys sheet, one-touch journeys hold 79.5% of revenue and take 0.5 days to buy. In those, the two reports have little to fight about. There is one visit, so there is one candidate for credit, and the purchase follows within about half a day.
The fight is in the rest. On the Journeys sheet, journeys with two or more touches hold 20.6% of revenue: 12.2% plus 5.4% plus 3.0%. The Journeys sheet also shows them taking 12.5 to 16.9 days to buy.
On the Journeys sheet, multi-touch journeys are 3,656 of the 3,670 distinct path sequences, yet hold about a fifth of revenue. Those are distinct routes, not purchases. Almost all the variety in how people reach a sale sits where channels share the path.
About two weeks is long enough for a click and its purchase to land in different reporting weeks. Google Ads books the conversion on the click date. GA4 books it on the purchase date. Compare the same week in both, and you are comparing different sales.
Long journeys also carry more channels. Google Ads counts the whole sale for its own ads. GA4 has to split one sale across everything in the path, or hand it to whatever closed.
What the export cannot show: which of those journeys held a Google ad, what anything cost, or how many sales sit behind each share. It is one store, not a benchmark.
Why does the usual answer mislead?
The checklist makes the gap sound like a setup bug. Mostly, it is the design.
Google Ads reports a conversion only when one of its own ads was involved. Its help page says so plainly: conversions need Google Ads interactions from the same account. It never asks what else the buyer did.
GA4 sees every channel and has to share one sale among them. Under its paid and organic last click model, a path that ends in an email click gives Email 100% of the sale. The Google ad that started the path gets nothing in that report, and the whole sale in Google Ads.
Time moves the goalposts too. Google's help says conversions can be reported up to 90 days after the click. Each one lands on the click's date, so last month's Google Ads total can keep rising. GA4 files the same sales under the days they happened.
Google Ads can also count sales it never directly observed. Its Conversions column may include modeled conversions where not every conversion can be seen. Cross-device conversions are modeled too.
And the column you compare matters. View-through conversions sit in All conversions, not in Conversions. Compare All conversions with GA4, and every impression-only sale widens the gap.
What can the Google Ads number not tell you?
Whether the click caused the sale. A buyer who searched your brand name and clicked your ad might have bought anyway. Google Ads counts that sale. GA4 counts it too, under Paid Search, if that click came last. Neither report can say what would have happened without the ad. A holdout test can, and incrementality testing shows how one works.
It also cannot tell you what the other channels did. A Google Ads conversion says a Google ad sat somewhere in the path. It says nothing about the email, the podcast or the friend who played a part too.
What to do this week
- Count your primary purchase actions. In Google Ads, click the Goals icon, open the Conversions drop-down and select Summary. Pass: one primary action records each purchase. Fail: a Google Ads tag and a GA4 import both count purchases as primary, so one sale can count twice.
- Compare on purchase dates. In your campaigns table, click the Columns icon, select Modify columns and add Conversions (by conv. time). Pass: the gap with GA4's google / cpc purchases narrows for the same week. Fail: it barely moves, so credit, not dates, drives the gap.
- Match the time zones. In GA4, go to Admin, then under Property click Property details and read the reporting time zone. Pass: it matches your Google Ads account's time zone. Fail: it differs, so sales near midnight land on different days in each report.
Check the homework. Your GA4 Attribution paths export already holds the evidence. Causality Engine reads that one file and shows what each channel caused next to what last-click gave it, in 1 to 2 minutes, for €99 once (excluding VAT), refundable within 30 days. Check the homework
Sources, 1 October 2026: Data discrepancies: Factors and troubleshooting (Google Ads Help). Understand your conversion tracking data (Google Ads Help). Get started with attribution (Google Analytics Help). About "All conversions" (Google Ads Help). About conversion windows (Google Ads Help). Add or remove columns in your statistics table (Google Ads Help). Select attribution settings (Google Analytics Help). Edit or delete accounts, properties and data streams (Google Analytics Help).
Related answers
Frequently asked questions
How big a gap between Google Ads and GA4 is normal?
Google's own help page says discrepancies of "often up to 20%" are expected, mostly from different attribution models. A bigger or sudden gap usually points at setup: a second primary purchase action, view-throughs in the column you compare, or mismatched time zones.Does Google Ads count a sale that GA4 gives to email?
Yes. Google Ads only reports conversions that had a Google Ads interaction, and it does not look at your other channels. If the buyer clicked your ad and later bought from an email link, Google Ads counts it. GA4's last click model gives it to Email.Does the gap mean Google Ads is lying?
No. Google Ads reports the sales that followed its own ads, dated to the click, under its own settings. GA4 answers a different question with different rules. Neither says whether the ad caused the sale; a holdout test does.
Go deeper: Incrementality testing, explained.
Sixty-second versions of these ideas: Causality Engine on YouTube Shorts.
Keep reading
Terms in this article
- AttributionAttribution identifies user actions that contribute to a desired outcome and assigns value to each. It reveals which marketing touchpoints drive conversions.
- Attribution WindowAttribution Window is the defined period after a user interacts with a marketing touchpoint, during which a conversion can be credited to that ad. It sets the timeframe for assigning conversion credit.
- ConversionConversion is a specific, desired action a user takes in response to a marketing message, such as a purchase or a sign-up.
- Google AdsGoogle Ads is an online advertising platform where advertisers bid to display ads, service offerings, and product listings.
- Google AnalyticsGoogle Analytics is a web analytics service that tracks and reports website traffic.
- Holdout TestA holdout test is an experiment where a portion of the audience does not see a campaign. This measures the campaign's true incremental impact.
- IncrementalityIncrementality measures the true causal impact of a marketing campaign. It quantifies the additional conversions or revenue directly from that activity.
- Incrementality TestingIncrementality Testing measures the additional impact of a marketing campaign. It compares exposed and control groups to determine causal effect.