Google Analytics 4 Setup for an Ecommerce Store, Step by Step

Installing the Google Analytics 4 tag takes ten minutes. Making GA4 tell the truth about your store's revenue takes a dozen settings that most stores skip: retention, filters, payment referrals, consent and key events. This checklist covers each one, in the order to do them, with the exact menu in GA4 and the rule from Google's own help pages.

The events your store sends (view_item, add_to_cart, purchase and their parameters) have their own guide: GA4 ecommerce events. This page is everything around them.

The GA4 ecommerce setup checklist at a glance

1. Create the property and web data stream

One property per store keeps revenue in one place. Separate brands or business units can get their own properties under the same company account.

Google says data collection may take up to 30 minutes to begin after the tag is live. The Realtime report is where you check.1Google Analytics Help, Set up Analytics for a website and/or app

2. Install the tag one way, and only one

The right method depends on your store platform. What matters most is that you pick one.

Sources: Google's setup guide and its Shopify article.1Google Analytics Help, Set up Analytics for a website and/or app2Google Tag Manager Help, Shopify: Set up your Google tag On Shopify, you don't need to connect Merchant Center to set up GA4, and GA4 can't track events until you deactivate your store's private mode.3Shopify Help Center, Setting up Google Analytics 4

Want to know what a tag or pixel actually sends, and why browser tags lose data? See what pixel tracking is.

3. Turn on enhanced measurement, then trim it

Enhanced measurement collects events without code. It's on by default when you create a stream, and each toggle sits under Admin > Data streams > your stream.4Google Analytics Help, Enhanced measurement events

Google adds one requirement that applies to every event: you're responsible for making sure no personally identifiable information is collected.4Google Analytics Help, Enhanced measurement events Emails in URLs, like a confirmation page with ?email= in it, break that rule.

4. Set data retention to 14 months

Standard GA4 properties keep user-level and event-level data for 2 or 14 months. Analytics 360 adds 26, 38 and 50 months.5Google Analytics Help, Data retention Pick 14 under Admin > Data settings > Data retention.

The same page has a "reset on new activity" option: turned on, it resets the retention period of a user's identifier each time that user comes back. It only applies to user-level data.5Google Analytics Help, Data retention Demographic data (age, gender, interests) is always kept for 2 months, whatever you choose.

5. Filter out internal traffic

Every test order your team places is a purchase in GA4 unless you filter it. The filter has two parts: a rule that labels your traffic, then a filter that excludes the label.6Google Analytics Help, Filter out internal traffic

Google is clear about the stakes: once a filter is active, "the excluded data is never processed and will never be available in Analytics or BigQuery".6Google Analytics Help, Filter out internal traffic That's why the Testing state exists. Other limits: 10 data filters per property, IP conditions that work as OR, and 24 to 36 hours before a filter takes effect. If you only want to hide data in one report, use a report filter instead.

Google also recommends filtering out developer traffic while debug mode is on, which is what you'll use in step 12. The Data filters screen has a Developer traffic filter type for that.16Google Analytics Help, Monitor events in DebugView

6. Stop payment pages from stealing the sale

This is the store-specific step most guides rush. When a buyer leaves your checkout to pay on another domain, then comes back to your confirmation page, GA4 sees that domain as the referrer. The purchase gets credited to the payment page, and the ad that brought the buyer loses it.

Google's own example for this setting is a store sending customers to a third-party payment processor and back.7Google Analytics Help, Identify unwanted referrals The fix:

1. Admin > Data streams > your web stream > Configure tag settings > Show all.
2. Click List unwanted referrals.
3. Add each domain your buyers can be sent to during payment: PayPal, a buy now, pay later provider's page, a hosted payment page, or a bank's 3-D Secure page when your payment flow redirects to it.
4. Save. You can add up to 50 conditions per stream.

GA4 then adds ignore_referrer=true to the matching events, so the referrer isn't shown as a traffic source. It isn't retroactive: a buyer who already came through the payment domain can still be attributed to it on a later direct visit.7Google Analytics Help, Identify unwanted referrals

Unwanted referral or cross-domain?

Cross-domain needs the same G- ID from the same data stream on every domain, and redirects that drop query parameters can strip _gl along the way.8Google Analytics Help, Set up cross-domain measurement The full method is in our guide to cross-domain tracking.

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7. Adjust the session timeout if your checkout is long

A GA4 session ends after 30 minutes without activity, and a session counts as engaged after 10 seconds. Both can be changed in the stream's tag settings under Adjust session timeout.9Google Analytics Help, Adjust session timeout If buyers routinely leave a tab open to compare before paying, a longer timeout keeps the purchase in the session that started with the ad. Most stores can keep the default.

8. Set up consent mode v2

If your store shows a cookie banner, consent mode is how the Google tag learns what the visitor chose. Google updated it in November 2023 with two extra parameters, and says it's strengthening enforcement of its EU user consent policy.10Google Tag Platform, Set up consent mode on websites

The default state is set on every page, before any config or event command. Google's example sets everything to denied, and a region list lets you apply that only where your laws require it:

gtag('consent', 'default', {
  'ad_storage': 'denied',
  'ad_user_data': 'denied',
  'ad_personalization': 'denied',
  'analytics_storage': 'denied',
  'wait_for_update': 500
});

wait_for_update gives a banner that loads asynchronously 500 ms to send the visitor's choice before tags fire. Your consent platform then sends an update command with what the visitor accepted.10Google Tag Platform, Set up consent mode on websites

Both are described on Google's consent mode page.11Google Analytics Help, Consent mode Which one your store may use is a legal question for your counsel and your consent platform, not a tracking one.

9. Mark your key events

Key events are what GA4 used to call conversions: the events that matter to the business, and the ones Google Ads can import. Purchase is a key event by default on web. If you link Google Ads with ads personalization on, GA4 also marks add_to_cart, begin_checkout, view_item, view_item_list, view_search_results, add_to_wishlist and session_start.12Google Analytics Help, Mark events as key events

Marking an existing event needs the Editor role; creating a new key event needs Marketer or above.12Google Analytics Help, Mark events as key events Which ecommerce events to send, and with which parameters, is in GA4 ecommerce events.

10. Link Google Ads and Search Console

Both links live under Admin > Product links.

Sources: Google's help pages on the two links.13Google Analytics Help, Link Google Ads and Analytics14Google Analytics Help, Search Console integration For campaigns outside Google Ads (email, Meta, affiliates), tag your links with UTM parameters so GA4 can name the source. Comparing tools that do this across channels? See conversion tracking tools.

11. Turn on BigQuery export

GA4's reports show aggregated data. BigQuery export gives you the raw events: every purchase with its parameters, which you can join to your orders table. The link is in Admin > Product links > BigQuery links.15Google Analytics Help, BigQuery Export

The first two figures come from Google's BigQuery Export page, the last two from the key events and unwanted referrals pages.15Google Analytics Help, BigQuery Export12Google Analytics Help, Mark events as key events7Google Analytics Help, Identify unwanted referrals A free BigQuery sandbox exists, but exports above its limits are billed, and storage and queries cost on the BigQuery side. Data exported once can't be exported again.15Google Analytics Help, BigQuery Export Google's page doesn't offer a backfill, so the sooner you link, the more history you own.

12. Test with a real order before you trust it

Turn on debug mode with Tag Assistant or Tag Manager's Preview: it adds a parameter to the URL. With gtag, add debug_mode: true to the config command; setting it to false doesn't turn it off, you have to remove it. Events then show under Admin > DebugView.16Google Analytics Help, Monitor events in DebugView

Run one full order: product page, cart, checkout, payment, confirmation. Then check what you see against your store's order.

Google notes that events don't appear in DebugView if consent mode is used and the visitor hasn't consented to analytics cookies, and recommends filtering out developer traffic so your tests don't land in reports.16Google Analytics Help, Monitor events in DebugView

GA4 will never match your store exactly: consent refusals and blocked scripts remove part of the traffic. When the gap matters for ad spend, the answer is to send the purchase from your server as well. That's what server-side tracking does.

Server-side tracking with Tagada

Whatever you use, the order of work doesn't change: one clean install, the twelve settings above, one real test order, then traffic.