Why Is My Google Ads Conversion Tracking Suddenly Not Working?
by Jaz Field
When Google Ads conversion tracking suddenly stops working on a Shopify store, the cause is almost always a change: to the checkout, the Google & YouTube app, a conversion action, the consent banner, or the landing page URLs. Before fixing anything, check that the drop is real, because Google Ads reports conversions on the click date and recent days always look low.
Conversions in Google Ads drop to zero, or fall by half overnight. Smart Bidding starts pulling back spend. Shopify orders look normal.
That pattern means the orders are happening and Google Ads is not hearing about them. Here is how to find out why.
First, check the drop is real
Google Ads reports a conversion on the date of the ad click, not the date of the purchase. A shopper who clicks today and buys next Tuesday adds a conversion to today's numbers next Tuesday. As a result, the last few days in Google Ads always look lower than they will end up.
- Compare periods at least 7 days old. If last week looks normal and only the last two days are low, it is conversion lag.
- Compare with Shopify orders. If Shopify's online orders are flat and Google Ads conversions fell for a week or more, something is broken.
Where to look
| Symptom | Most likely cause | Where to check |
|---|---|---|
| Conversions dropped to zero | Purchase tag removed, or a new conversion action replaced the old one | Goals > Conversions > Summary, action status |
| Conversions fell by a large share | Consent settings or click ID loss | Conversion action Diagnostics, landing page URLs |
| Conversions doubled | Two Primary purchase actions | Goals > Conversions > Summary, Primary vs Secondary |
| Bidding ignores conversions | Action set to Secondary | Conversion action settings |
| Enhanced Conversions warnings | Customer data not sent or not matched | Conversion action Diagnostics |
1. A checkout change removed the purchase tag
Shopify has retired additional scripts on the thank-you and order status pages as part of its move to checkout extensibility. A Google Ads purchase tag that was pasted there, or installed by an old app, stops firing once the store moves to the new pages.
- Check: open the purchase conversion action. A status like "No recent conversions" or "Inactive" after a checkout change points here.
- Fix: send purchases through a supported route: the Google & YouTube app, a customer events pixel, or a server-side integration.
2. The Google & YouTube app created a new conversion action
Reinstalling the Google & YouTube app, reconnecting a Google account, or linking a different Google Ads account can create a new set of conversion actions. Your campaigns may still be bidding on the old one, which no longer receives data.
- Check: in Goals > Conversions > Summary, look for purchase actions with similar names and compare which one is recording conversions.
- Fix: make the action that receives data Primary, and set the old one to Secondary or remove it.
3. The conversion action is set to Secondary
Only Primary conversion actions count in the Conversions column and feed Smart Bidding. A purchase action switched to Secondary still records conversions, but campaigns stop seeing them. This often happens when someone adds a new action or changes goals.
- Check: the Primary or Secondary label next to each purchase action, and which conversion goals each campaign uses.
- Fix: keep one Primary purchase action per account and set every other purchase action to Secondary.
4. Consent settings stop the tag firing
If your consent setup only lets Google tags fire after a shopper accepts cookies, purchases from shoppers who decline are not recorded as normal conversions. A new consent banner, a change to its default settings, or a banner appearing in more regions can cut conversions overnight.
Google's consent mode lets tags send signals without cookies, so Google can model some of the missing conversions. That only works when consent mode is set up correctly.
- Check: the conversion action's Diagnostics tab for consent warnings, and whether the drop started when the banner changed.
- Fix: make sure the banner passes consent mode signals to Google, and that the purchase tag respects them rather than being blocked outright.
5. The click ID is lost before the shopper lands
Google Ads ties a conversion to a click using the click ID, the gclid parameter that auto-tagging adds to the landing page URL. If the ID is lost, Google cannot connect the purchase to the ad.
- Auto-tagging turned off in the Google Ads account settings.
- Redirects that drop URL parameters, for example after a domain change or a theme that rewrites URLs.
- Landing page changes that send shoppers to a different domain before checkout.
To check, click one of your own ads and confirm gclid is still in the address bar when the page loads.
6. Enhanced Conversions stopped matching
Enhanced Conversions sends hashed customer details, such as email and phone, with the purchase so Google can match it to a signed-in user. If the data stops arriving, fewer conversions are attributed.
- Check: the Enhanced Conversions section of the purchase action's Diagnostics. It shows whether customer data is received and how much of it matches.
- Fix: confirm the customer data terms are accepted in Google Ads and that the tag or integration still sends the hashed fields after any checkout change.
7. Purchases are counted twice, then "fixed" to half
Sometimes conversions "suddenly drop" because they were double counted before. If both the Google & YouTube app and a Google Tag Manager tag, or an imported GA4 key event, counted purchases as Primary, removing one halves the number. The new number is the real one.
- Check: compare Google Ads purchase conversions with Shopify's online orders for a past week. Conversions above orders mean double counting.
The free Littledata Tracking Audit lists every Google tag on your storefront and flags duplicates.
How to stop it breaking again
Most of these failures come from the purchase depending on a browser tag that a checkout change, app update or consent setting can switch off without warning.
- Keep one Primary purchase action and write down where its data comes from.
- Check Google Ads against Shopify weekly, using a period at least 7 days old.
- Recheck after every change to the checkout, the Google & YouTube app, the consent banner or landing page URLs.
- Send purchases server-side. The Shopify Google & YouTube app sends conversions from the browser. Littledata sends every order to Google Ads from Shopify's servers with Enhanced Conversions built in, as an additional data source on your Primary action, so Google deduplicates on the Shopify order ID. See Shopify to Google Ads with Littledata.
For why server-side Enhanced Conversions can change how many conversions Google credits, see why Enhanced Conversions might result in fewer conversions attributed to Google Ads.
Frequently asked questions
Why did my Google Ads conversions suddenly stop?
The most common causes on Shopify are a checkout upgrade that removed an old purchase tag, a reinstall or reconnection of the Google & YouTube app that created a new conversion action, a conversion action switched from Primary to Secondary, consent settings that stop the tag firing, and auto-tagging or redirects that strip the click ID. Check the conversion action's status and diagnostics in Google Ads first.
Why do my recent Google Ads conversions look low?
Google Ads reports a conversion on the date of the ad click, not the date of the purchase. A shopper who clicked yesterday and buys next week is added to yesterday's numbers later. The last few days always look low and fill in over time, so compare periods at least a week old before deciding tracking is broken.
How do I check if my Google Ads conversion tag is working?
In Google Ads, go to Goals > Conversions > Summary and open the purchase action. The status shows whether it is recording conversions, and the Diagnostics tab lists problems Google has detected. Then place a test order through an ad click and confirm the conversion arrives, allowing a few hours.
Can consent mode stop Google Ads conversion tracking?
Yes. If Google's consent mode is set up so that tags only fire after consent, purchases from shoppers who decline are not sent as normal conversions. A change to your consent banner, or a region where the banner now appears, can cut recorded conversions overnight. Google can model some of these, but only when consent mode signals are sent correctly.
Why are my Google Ads conversions counted twice?
Usually because more than one conversion action counts purchases and both are set as Primary, for example one from the Google & YouTube app and one from Google Tag Manager or an imported GA4 key event. Keep one Primary purchase action and set the others to Secondary.
Does server-side tracking stop Google Ads conversions breaking?
It removes the most common failure points. Server-side purchases are sent from Shopify for every order, so they do not depend on checkout scripts, browser tags or the shopper staying on the thank-you page. Consent and conversion action settings still need checking.
The short version
Rule out conversion lag, then look for what changed: the checkout, the Google & YouTube app, a conversion action's Primary setting, the consent banner or the landing page URLs. One of those is behind most sudden Google Ads tracking failures on Shopify.
