Linking GA4 and Google Ads: keyword-level behaviour and audiences

Most people link GA4 and Google Ads to import conversions and audiences. In my view the most useful part is something else: once the two are linked, GA4 shows you how visitors from each individual keyword behave on your site. That matters when two keywords bring in enquiries equally well and the budget has to go to one of them. And it simply gives you more and better data than Google Ads shows on its own.

Below: what actually appears after linking, how to use it, a short word on audiences, and the setup step by step.

1. What linking GA4 and Google Ads gives you: behaviour for every keyword

Google Ads sees the ad before the click and the conversion after it: impressions, clicks, cost per click, enquiries. What someone did on your site between the click and the enquiry, or instead of the enquiry, the ad account doesn’t know. GA4 does, but without the link it doesn’t know which keyword the visitor came from.

After linking, GA4 fills in campaign, ad group, keyword and search query dimensions for each session. According to Google’s help pages these are populated automatically once the accounts are linked. If you delete the link, new clicks show up in these dimensions as (not set).

For keyword decisions, two dimensions matter most:

• Session Google Ads keyword text: the keyword that triggered the ad.
• Session Google Ads query: what the person actually typed into the search box.

Pair them with the behaviour metrics:

• Engagement rate: the share of engaged sessions. By Google’s definition an engaged session lasts longer than 10 seconds, or has a key event, or has at least two page views.
• Average engagement time per session.
• Engaged sessions and Key events.

Two keywords perform the same, and you have to pick one

This is the situation that makes the link worth it for me. For example (the numbers are made up): a roofing company advertises in Germany, and over a month two keywords each bring 6 enquiries at almost the same cost per enquiry.

• “dachsanierung kosten”: 240 sessions, engagement rate 71 %, average engagement time 1 min 35 s.
• “dachdecker notdienst”: 230 sessions, engagement rate 39 %, average engagement time 22 s.

On enquiries it’s a draw. On behaviour it isn’t. Most people from the first keyword read the page; most people from the second leave quickly, and the 6 enquiries came from a small slice of them. Raise the bid on the second keyword and you will most likely buy more quick exits. The first keyword brings plenty of people who are interested but haven’t decided yet, and remarketing can bring them back. If the budget has to go to one keyword, I would give it to the first.

The same report is useful without a two-way choice, too. A keyword with lots of clicks and a low engagement rate usually means one of two things: the wrong search queries sit behind it, or the page doesn’t answer what the query asked. The query dimension shows you straight away what people actually searched for.

Careful with the conclusions

• Compare rates, not absolute numbers, and only once both keywords have enough sessions. With a few dozen sessions, a gap of 10 to 15 points can easily be chance.
• If the keywords lead to different pages, you are comparing the pages as well. The comparison is fairest when the page is the same.
• In Germany, GA4 only fully sees visitors who consented. § 25 TDDDG requires consent before a site stores anything on a visitor’s device or reads from it. So GA4 records fewer sessions than Google Ads records clicks, and each keyword’s sample is smaller. For comparing two keywords with each other that’s workable, but don’t hold Google Ads clicks directly against GA4 sessions. More in tracking and consent in Germany.

2. GA4 audiences in Google Ads, briefly

The second reason to link: audiences. You build an audience in GA4, for example every visitor without an enquiry in the last 30 days, and after linking it appears in Google Ads as a list for remarketing or for exclusion.

Three things worth knowing up front:

• Personalised advertising has to be on in the link settings. In GA4 the toggle is on by default. If you link from Google Ads, importing Google Analytics audiences is a separate toggle.
• The audience is smaller in Google Ads than in GA4. Google only shows the part that can be used for advertising there. Someone who opted out of ads personalisation stays in GA4 reports but is left out of the list exported to Google Ads. If consent mode sends ad_personalization = denied, remarketing in Google Ads receives no data for that visitor.
• Without a reliable enquiry event, exclusion doesn’t work. If generate_lead doesn’t always fire, your ads keep showing to people who have already enquired.

How to build audiences by time window and cleanly exclude everyone who has already converted is covered in detail in GA4 remarketing for Google Ads. I won’t repeat it here.

3. How to link GA4 and Google Ads: step by step

Check permissions first. In GA4 you need the Editor or Administrator role on the property, in Google Ads administrative access. You also need auto-tagging in Google Ads: without it the keyword and query dimensions stay empty.

You can create the link from either side. The result is the same, and one link is enough.

Option A: from GA4

1. Go to Admin → Product links → Google Ads links.
2. Click Link, then Choose Google Ads accounts and select your account. Click Confirm and Next.
3. Leave Enable Personalized Advertising switched on. Without it your audiences won’t work in ads.
4. Expand Enable Auto-Tagging and switch it on if it isn’t already.
5. Click Next, review the settings and click Submit.

Option B: from Google Ads

1. Click the Tools icon → Data manager → + Connect Product.
2. Under “Data source” choose Google Analytics (GA4) & Firebase, find your property and click Next.
3. Switch on the toggles for importing app and web metrics and Google Analytics audiences. Click Link.

Where to find the keyword data

1. Allow up to 48 hours. That’s how long Google says it takes for Google Ads data to appear in GA4 reports.
2. The ready-made report in GA4: Reports → Acquisition → Overview → on the “Sessions by Session Google Ads campaigns” card click “View Google Ads campaigns”. Switch the dimension in the drop-down above the table to the keyword or the query. Engagement rate, average engagement time per session and key events are already in the report.
3. Your own exploration, if you want more flexibility: Explore → Free form template. Put Session Google Ads keyword text in rows and sessions, engagement rate, average engagement time per session and key events in values. A filter on the Google Ads campaign narrows it to the campaign you care about.
4. Inside Google Ads: Google’s help describes GA4 columns in Google Ads reports, including on the Search keywords tab: Columns → the “Google Analytics” group → for example “% Engaged sessions (GA4)” and “Avg. engagement duration per session (seconds) (GA4)”. This needs the web metrics import switched on in the link, and the data usually shows up within an hour. If the column group is missing, check the link status in Data manager. The GA4 report is the more dependable route either way, because only there do you see the search query next to the keyword.

The bottom line

• The main value of the link is engagement rate and engagement time for every keyword. When two keywords bring the same number of enquiries, visitor behaviour tells you which one is more likely to hold up with more budget.
• Compare rates with enough sessions behind them, and remember that in Germany GA4 only sees visitors who consented.
• GA4 audiences reach Google Ads only with personalised advertising switched on, and only for visitors who agreed to personalisation.
• The link takes a few minutes, from GA4 or from Data manager in Google Ads. You need Editor access in GA4, admin access in Google Ads, and auto-tagging.

Not sure the link works and the keyword data can be trusted? In a free intro call I’ll look at GA4 and Google Ads with you and tell you honestly what the data shows. Book a free intro call.

FAQ

Do I need the link if the Google Ads tag already counts conversions?

Yes. The Google Ads tag counts conversions, but it doesn’t show what visitors from each keyword did on your site, especially the ones who didn’t enquire. And GA4 audiences won’t reach Google Ads without the link either.

Why does GA4 show fewer sessions than Google Ads shows clicks?

Google Ads counts clicks, GA4 counts sessions. One person can click an ad several times within one session, or leave before the page has loaded. In Germany, consent comes on top: whoever declines isn’t fully visible in GA4. So a noticeable gap between the two numbers is normal.

Can I link one GA4 property to several Google Ads accounts?

Yes. Google allows up to 400 links per property, and a link to a manager account counts as one.

What happens if I delete the link?

New clicks show up in the Google Ads dimensions as (not set), GA4 audiences stop adding new users for that account, and key events stop importing into Google Ads. Historical data in GA4 stays.