Web and product analytics
Why GA4 numbers don't match Google Ads, Shopify or your CRM
The short answer
Different tools count different things in different ways. GA4 misses visitors who decline consent or block scripts, credits conversions with its own attribution model and dates, and hides small numbers when Google signals is on. Google Ads reports conversions against the click date, Shopify counts orders from its own checkout, and your CRM counts leads it actually received. A gap of 10 to 30% is normal; a gap that suddenly changes is worth investigating.
Key takeaways
- Consent, ad blockers, attribution models, click-date reporting and thresholds all move the numbers.
- Use your store or CRM for counts of orders and leads, and GA4 for sources and behaviour.
- A steady gap is normal; a gap that suddenly changes points to a broken tag.
On this page 8 sections
The common causes
| Cause | Effect | Which tool is right |
|---|---|---|
| Consent declined | GA4 records fewer users and conversions in regions with banners | Your backend (orders, CRM) for counts |
| Ad blockers and browser privacy | GA4 and ad tags miss a share of visitors | Your backend for counts |
| Attribution model | GA4 data-driven and Google Ads data-driven can split credit differently; GA4 can credit organic or email where Ads claims the click | Neither: they answer different questions |
| Conversion date | Google Ads reports a conversion against the day of the ad click; GA4 against the day it happened | Both, for their own purpose |
| Data thresholds | GA4 withholds rows with small user counts when Google signals is on | Turn on device-based reporting identity to reduce it |
| Sampling in explorations | Explorations over very large date ranges are estimated from a sample | Standard reports are unsampled |
| Definitions | Shopify sessions, Search Console clicks and GA4 sessions are defined differently | Compare trends, not totals |
| Time zone and currency | Day boundaries and revenue shift if property and store settings differ | Align the settings |
GA4 vs Google Ads
If you import GA4 key events into Google Ads, Ads will usually show fewer conversions than GA4 shows for the same event, because Ads counts only conversions it attributes to an ad click, within your conversion window, and reports them against the click date. Recent days in Ads also fill in over time as late conversions arrive. Compare over a closed period at least a conversion window old.
GA4 vs Shopify (or any store backend)
Your store's order count is the truth for orders. GA4 purchase events go missing when consent is declined, when a script is blocked, when the thank-you page does not load, or when the purchase event is not wired to the store's checkout events. If GA4 records under about 80% of orders where you have no consent banner, check the purchase tag first.
GA4 vs Search Console
Search Console counts clicks on Google search results. GA4 counts sessions it attributes to google / organic, which excludes visitors who declined consent and includes some it could not attribute elsewhere. Search Console also anonymises some rare queries. Use Search Console for search demand and GA4 for what happened after the click.
GA4 vs your CRM
A CRM counts leads that arrived, including those from phone calls GA4 never saw and repeat submissions it would merge. It is the only place that knows which leads turned into customers. If you want marketing reports in revenue rather than form fills, record the source on each lead (UTMs and click IDs in hidden fields) and report from the CRM, or use a lead tracking platform that does it for you.
A short audit
- Check the GA4 property's time zone and currency match your store and ad accounts.
- Confirm each key event fires once per action (no duplicates from both a GTM tag and a hard-coded tag).
- Compare GA4 purchases with backend orders for a closed week, by device and country, to see where losses concentrate.
- In Reporting identity, try device-based to see how much thresholding is hiding.
- Raise event data retention to 14 months so year-on-year explorations work.
Questions
- Why does GA4 show more conversions than Google Ads?
- Google Ads counts only conversions it attributes to an ad click within the conversion window and reports them on the click date. GA4 counts every occurrence of the key event and credits it to whichever channel its own model chooses.
- What is data thresholding in GA4?
- When Google signals is enabled, GA4 hides rows in reports where the user count is small enough that individuals might be identified. Switching the property's reporting identity to device-based usually reduces it.
- Which number should I report to my boss or client?
- Report outcomes from the system that records them (orders from the store, leads and revenue from the CRM) and use GA4 to explain trends and channels. Say which source each number comes from.
Sources
Next step
Compare the tools for this job
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