GA4 remarketing for Google Ads: wiring your audiences up properly

GA4 remarketing is quick to explain and still gets wired up wrong constantly. You build audiences in Google Analytics 4 from visitors who didn’t trigger your lead or purchase event, and you serve those exact people again through Google Ads. In practice it falls over in two places — the audience logic (who do you include, who do you exclude, over what window?) and the link between Google Ads and the GA4 property, without which not a single audience ever reaches the ad account. Here’s the whole build, step by step.

1. Why GA4 audiences beat Google Ads lists

GA4 remarketing means building your audiences in GA4 rather than in Google Ads, then importing them into the ad account. The detour pays off because GA4 knows far more about your visitors than the Google Ads tag alone: every event, every page, every session. That lets you define precisely who you want to reach again — for example everyone who didn’t trigger your lead or purchase event.

Those non-converters are the most valuable remarketing segment you have: people who already know you but haven’t enquired yet. In this article we build them in clean time windows — 7, 14, 30, 60 and 90 days — and wire them so Google Ads actually receives them. The link is where most setups fail.

2. Building the audiences: every visitor who didn’t trigger your lead or purchase event

The most common bad build is a single “all visitors” list that then re-advertises to everyone, customers included. Clean looks like the opposite:

• Include: all users who were on the site.
• Exclude: everyone who triggered the conversion event (generate_lead or purchase).
• Stagger: the same logic across five windows — 7, 14, 30, 60 and 90 days.

Why stagger it? Because recency is the strongest signal you have. Someone who looked at your offer 5 days ago is hotter than someone from 80 days ago, and deserves a higher bid and a more direct message. Five windows let you differentiate that properly in Google Ads later, instead of bidding on everyone the same way.

Step by step in GA4

1. Admin → Data display → Audiences → “New audience” → “Create a custom audience”.
2. Include condition: event session_start — that puts everyone who visited the site in the list.
3. “Add group to exclude”: event generate_lead (or purchase for a shop). Set the exclusion to permanently exclude — whoever converted drops out and doesn’t come back. (Exception: shops with regular repeat purchases may want the exclusion to be temporary.)
4. Membership duration: 7 days. That’s your time window.
5. Give it a clear name, e.g. Remarketing | no lead | 7 days. In Google Ads you’ll only see a flat list later, and “Audience 3” helps nobody there.
6. Save, then repeat the build for 14, 30, 60 and 90 days. You end up with five audiences, identical logic, different membership duration.

Add a sixth list on top: the converters (include: generate_lead or purchase). You need that one in Google Ads as an exclusion list, so your prospecting campaigns stop bidding on people who have already converted.

The traps at this stage

• Audiences fill from the moment you create them, retroactively 30 days at most, and only if the data is there. So build them today, not on the day the campaign is meant to launch.
• Criteria can’t be edited after saving — only the name and description. A mistake in the condition means building it again. Think it through first rather than swearing afterwards.
• GA4 allows a maximum of 100 audiences per property — with a naming convention and no sprawl, that stays comfortable.
• The windows overlap: the 30-day list contains the 7-day users. That’s fine. You build exclusive bands later in Google Ads, e.g. by targeting the 30-day list and excluding the 7-day list.

And check the most important trap first: if generate_lead doesn’t fire on your site, or fires unreliably, your exclusion condition is empty — and you’re cheerfully advertising to your own customers. Verify the events, then build the lists.

3. The link through Data Manager — without it no audience ever arrives

This is the step most guides handle in a subordinate clause, and the reason so many accounts hold beautiful GA4 audiences that Google Ads has never seen. Without the link between Google Ads and the GA4 property, nothing flows. No audiences, no data. The lists just sit in GA4 like letters without an address.

Creating the link

The direct route runs through Data Manager in Google Ads:

1. In Google Ads: Tools → Data Manager.
2. Connect Google Analytics (GA4) as a product and pick your GA4 property. You need admin rights in Google Ads and at least editor rights on the property.
3. When creating the link, turn on personalised advertising. That switch is the decisive one: it’s what makes GA4 audiences available for ad targeting in Google Ads. A link without that box ticked is a link without remarketing.
4. Confirm — done.

The same link can be created from the GA4 side (Admin → Product links → Google Ads links). The result is identical; what matters is only that the link exists and personalised advertising is active.

Checking that the audiences arrive

In Google Ads under Tools → Shared library → Audience manager, your GA4 lists now show up as data segments with the source “Google Analytics (GA4)”. Two things need patience:

• Fill level: freshly linked lists start at zero and grow with traffic. Give them a few days.
• Minimum sizes: Google only serves segments once they’re big enough — from 100 active users for Display, Demand Gen and YouTube, from 1,000 on the Search Network. Below that the list exists but doesn’t get served. On low traffic, the long windows (60/90 days) are often the only ones that clear the threshold — another reason to stagger.

And then put them to work

• Search: attach the lists to your campaigns as observation first, not targeting — targeting shrinks your reach down to the list. After a few weeks the report shows you how returning visitors perform, and you can set bid adjustments: aggressive on the 7-day window, moderate on 90 days.
• Display / Demand Gen / YouTube: here they go in as real targeting — classic remarketing to everyone who didn’t convert.
• Converter list as an exclusion in every prospecting campaign. That’s half the value of the whole exercise: no more budget spent on people who submitted the form long ago.

The bottom line

GA4 remarketing is no black art — it’s three clean moves in the right order:

• The link is the crux. Anyone can build audiences; they only arrive with a clean GA4-to-Google-Ads link through Data Manager.
• Audience logic: include all visitors, exclude anyone who triggered generate_lead or purchase — across five windows (7, 14, 30, 60, 90 days), plus a converter list as an exclusion.
• Check the events before building the lists. An empty exclusion condition advertises to your own customers, and criteria can’t be edited afterwards.
• The Data Manager link is mandatory, personalised advertising included — otherwise the audiences never reach Google Ads.
• Plan for the minimum sizes: 100 active users for Display and Demand Gen, 1,000 for Search.

Set this up once properly and you have a permanent system that brings warm visitors back, instead of only ever buying cold ones.

If you’re not sure your events fire cleanly or the link is really in place, write to me. I’ll go through GA4, Google Ads and your tracking with you — honestly, no sales show.