In the US, shoppers can now check out inside Copilot, Gemini and Google AI Mode.

Track AI checkouts in GA4, without rebuilding your tracking

Orders placed inside AI assistants never load your store, so your GA4 tag can’t record them. GapFill: GA4 Server Tracking compares your Shopify orders with GA4 and sends the missing purchases via the Measurement Protocol, along with everything else your tag missed. Your existing tag stays in place.

AI Assistant

Recovered AI orders are sent with the assistant as the source and ai-assistant as the medium, so they’re attributed to GA4’s AI Assistant default channel.

Run your free gap report How it works

Free GA4 vs. Shopify gap report
Nothing is sent until you approve
Your existing tag stays in place

Illustration of the GA4 gap report. Orders are examples.

AI assistants are becoming a sales channel. Your GA4 reports don’t show it yet.

In the US, shoppers can already ask Microsoft Copilot, Google AI Mode or Gemini for a product and pay without leaving the chat. These agentic checkouts never load your store, so your GA4 tag never fires and the revenue never shows up in your reports.

GapFill sends those orders to GA4 with the assistant as the source and ai-assistant as the medium, so they’re attributed to the AI Assistant default channel. You can see how much revenue AI is driving and compare it with search, social and the rest of your mix.

AI checkouts aren’t the only gap

GA4 records a purchase only when its tag fires in the buyer’s browser. When it doesn’t, the order exists in Shopify but not in GA4, and your revenue and channel performance are under-reported.

How a purchase gets into GA4

1Order placed
×
Lost hereThank-you page never loads
- Off-site payment, buyer never returns
- Subscription renewals
- Agentic checkout in AI chats
2Thank-you page loads
×
Lost hereTag never fires
- Ad blockers and browser tracking prevention
- Buyer leaves before the tag fires
3GA4 tag fires
4Tracked in GA4

In every case the order exists in Shopify but never reaches GA4, and fixing the tag alone won’t close the gap.

GapFill sends only what GA4 is missing

Your existing tag stays in place. GapFill waits for GA4 to finish processing, reconciles Shopify orders against GA4 purchases by transaction_id, and sends only the missing purchases server-side.

1
Wait 26 hours
GA4 finishes processing the purchases your tag tracked
Shopify orders
- #1001
- #1002
- #1003
- #1004
- #1005
- #1006
2
Reconcile by transaction_id
Shopify orders are matched against GA4 purchases
GA4 purchases (tag-tracked)
- #1001
- #1002
- Missing
- #1004
- Missing
- #1006
3
Send only missing purchases
Server-side, via the Measurement Protocol
Sent by GapFill
- #1003gapfill=1
- #1005gapfill=1
4
No duplicate purchases
Orders already in GA4 are skipped. Sent purchases are tagged gapfill=1
GA4 after GapFill
- #1001
- #1002
- #1003GapFill
- #1004
- #1005GapFill
- #1006

GapFill in 90 seconds

Client-side tag vs. server-side GTM vs. GapFill

The usual advice for these gaps is to move tracking to server-side GTM. For most of the merchants we work with, rebuilding the whole setup wasn’t worth it. GapFill leaves your tag alone and adds only what GA4 missed.

Topic	Client-side tagThe Google & YouTube app or gtag. Tracks a purchase only when the tag fires in the browser	Server-side GTMRoutes browser events through your own tagging server to GA4	GapFillKeeps your existing tag. Sends only the purchases GA4 missed, server-side
Recovers missing purchases	NoIf the tag doesn’t fire, the purchase isn’t tracked	PartialRecovers some purchases lost to ad blockers. In a typical setup, off-site payment drop-offs are still missed	BestSends every purchase GA4 missed, except buyers who declined analytics cookies
Agentic checkouts	NoNo storefront page loads, so nothing is tracked	NoIn a typical setup there’s no browser event, so nothing is tracked	BestSent with the AI assistant as the source, e.g. copilot.microsoft.com
Setup effort	BestNothing to change	NoA full migration of your tracking setup	BestInstall, sign in with Google, done
Cost	BestNo extra cost	PartialServer costs plus setup and maintenance time	YesFree report. Sending from $19/month
Before you commit	NoNo visibility into how much is missing	PartialYou see the impact only after migrating	BestThe free report shows what’s missing first

Recovers missing purchases Client-side tag：NoServer-side GTM：PartialGapFill：Best

Client-side tag: If the tag doesn’t fire, the purchase isn’t tracked
Server-side GTM: Recovers some purchases lost to ad blockers. In a typical setup, off-site payment drop-offs are still missed
GapFill: Sends every purchase GA4 missed, except buyers who declined analytics cookies

Agentic checkouts Client-side tag：NoServer-side GTM：NoGapFill：Best

Client-side tag: No storefront page loads, so nothing is tracked
Server-side GTM: In a typical setup there’s no browser event, so nothing is tracked
GapFill: Sent with the AI assistant as the source, e.g. copilot.microsoft.com

Setup effort Client-side tag：BestServer-side GTM：NoGapFill：Best

Client-side tag: Nothing to change
Server-side GTM: A full migration of your tracking setup
GapFill: Install, sign in with Google, done

Cost Client-side tag：BestServer-side GTM：PartialGapFill：Yes

Client-side tag: No extra cost
Server-side GTM: Server costs plus setup and maintenance time
GapFill: Free report. Sending from $19/month

Before you commit Client-side tag：NoServer-side GTM：PartialGapFill：Best

Client-side tag: No visibility into how much is missing
Server-side GTM: You see the impact only after migrating
GapFill: The free report shows what’s missing first

Tap a row for details

For a detailed comparison, see GA4 Not Tracking All Shopify Purchases? How to Find and Recover Missing Transactions.

Guardrails

Deduplicated by transaction_id: An order is never sent if GA4 already has its transaction_id, and GapFill checks again after sending.
Auto-pause on anomalies: If the gap suddenly spikes, GapFill assumes your tag broke and pauses, so it never masks a tracking problem.
Consent-aware: GapFill follows Shopify’s Customer Privacy settings. Orders from buyers who declined analytics cookies are never sent, and where consent is required, only orders with confirmed consent are.
Fully labeled: Every recovered purchase carries gapfill=1, so you can segment it from tag-tracked purchases in GA4.

How it works

01
Install and connect GA4
Sign in with Google and pick your store’s GA4 property. Nothing about your current tag changes.
02
Run the free gap report
See which of the last 30 days’ orders GA4 never recorded and the revenue at stake, broken down by channel, source / medium and payment method.
03
Approve, and GapFill backfills hourly
Every hour, orders still missing from GA4 26 hours after purchase are sent. You can review each one before you approve.

Pricing

The gap report is free. Sending to GA4 is on the Standard plan, with a 14-day free trial. Each purchase, refund or cancellation sent counts as one event.

Free

See what GA4 is missing

GA4 vs. Shopify gap report (last 30 days)
Breakdown by channel, source and payment method

Standard

$19/month

Recover missing purchases in GA4

Everything in Free
200 events/month included
$0.02–$0.05 per event after that
AI and social app checkouts, sent by default
Subscription renewals, refunds and cancellations, if you turn them on

Run your free gap report Pricing details

FAQ

Does GapFill replace my GA4 tag?

No. Keep your current setup. GapFill only sends purchases that GA4 didn’t track.

Could a purchase be counted twice?

An order is not sent if GA4 already has the same transaction ID. GapFill waits at least 26 hours for GA4 to finish processing before it decides.

How do AI checkouts show up in GA4?

The source is the AI assistant (gemini.google.com, copilot.microsoft.com and so on) and the medium is ai-assistant, so in event-scoped reports they’re attributed to GA4’s AI Assistant default channel.

Which orders does GapFill send?

By default, online store orders that GA4 didn’t track, and in-app checkouts in AI assistants and social apps. Subscription renewals, refunds and the rest are sent only if you turn them on in Settings.

How is customer consent handled?

GapFill follows Shopify’s customer privacy settings. Orders from buyers who declined analytics cookies are not sent, so GA4 and Shopify won’t match exactly.

How many orders do I need?

GapFill needs at least 20 purchases in GA4 to match them against your orders. Below that, the report says it can’t match yet.

Will my Google Ads conversions go up too?

GapFill sends purchases to GA4. Whether they count in Google Ads depends on whether your ads account imports GA4 conversions.

What happens if I uninstall?

Sending stops. Purchases already sent stay in GA4.

See all questions

Why I built GapFill

I’ve worked in ecommerce marketing since 2010: at an ad agency, at an on-site personalization vendor, running a DTC brand of my own, and at a Shopify app developer. Today my company, ULTRO, helps Shopify brands with everything from store builds to ads and CRM. The question I hear more than any other is a simple one: why doesn’t GA4 match Shopify?

It’s rarely a broken tag. Buyers pay off-site and never come back to the thank-you page. Ad blockers stop the tag. And now that checkout is moving inside AI assistants, some buyers never visit the store at all. Server-side tagging can fix part of this, but it’s a real project, and most merchants I worked with decided it wasn’t worth it.

So I built the tool I wanted to hand them: keep your tag, and send only what GA4 missed. As more shopping moves into AI assistants, I expect this gap to grow. Start with the free report and see what your own store is missing.

Ryushi NagataCEO, ULTRO Inc. (Tokyo)Profile

The help pages cover setup and common problems. For anything else, email gapfill-support@ultro.co.jp. See the privacy policy for how GapFill handles data.

See what GA4 is missing from your store

The gap report is free. Decide whether to send anything after you’ve seen the numbers.

Run your free gap report

Free GA4 vs. Shopify gap report
Nothing is sent until you approve
Your existing tag stays in place