To link GA4 to Google Ads, turn on auto-tagging, then open Admin > Product links > Google Ads links in GA4, click Link and pick the account, using a Google account that is Editor or Administrator on the property and an admin in Google Ads. Then import your lead key event in Google Ads and keep it secondary if you upload offline conversions, so bidding learns from the leads that became customers.
Before you link
Check 1: Is auto-tagging on?
WhereGoogle AdsAdminAccount settingsAuto-tagging
You should see: The box next to Tag the URL that people click through from my ad is checked. Google needs auto-tagging to import key event data from Google Analytics and lists it as a requirement for importing conversions.
If not: Check the box and click Save. How the gclid it adds works is covered in Google Ads auto-tagging.
Careful: A few sites serve an error page when a URL carries a parameter they do not expect. Run check 2 right away: if the page breaks, Google says to turn auto-tagging off until your developer allows arbitrary URL parameters.
Check 2: Does the gclid survive your redirects?
WhereGoogle AdsLanding pages
Do: Copy a URL from the table into the address bar without loading it, add
?gclid=TesTER-123 (or &gclid=TesTER-123 if the URL already has a question mark) and press Enter.You should see: The page loads and the address bar still shows
gclid=TesTER-123 with every symbol and capital letter unchanged (Google's test).If not: Find the redirect or plugin that drops or rewrites the parameter and change it. The gclid has to reach the final landing page for Google to track conversions.
Link the accounts
Check 3: Is the Google Ads account linked in GA4?
WhereGoogle AnalyticsAdminProduct linksGoogle Ads links
Do: Click Link, then Choose Google Ads accounts, select the account and click Confirm and Next. Expand Enable Auto-Tagging to turn it on if check 1 failed, then click Next and Submit (GA4: link Google Ads).
You should see: The account in the list of linked accounts. Google Ads data reaches your GA4 reports within 48 hours.
If not: If the account is not offered, you may lack the Admin role in it. In the row Request access to other Google Ads accounts, click Send request, enter its account ID and click Confirm, which notifies its admins.
Careful: If you enable auto-tagging while linking a manager account, auto-tagging turns on in every Google Ads account directly linked to it, and whatever you import from GA4 becomes available to all its client accounts.
Check 4: Does Google Ads show the same link?
WhereGoogle AdsToolsData manager
Do: Under Connected products, find Google Analytics (GA4) and Firebase and click Manage & link.
You should see: Your property in the table, with a Date linked and a Status column that shows which data comes in from GA4 (Google Ads: link GA4). A link made in GA4 shows up here too.
If not: Link from this page instead: click + Connect Product, choose Google Analytics (GA4) & Firebase, select the property, click Next, then Link. This route needs Edit permission on the property.
Import the key event
Check 5: Is your lead event marked as a key event?
WhereGoogle AnalyticsAdminData displayEvents
Do: In the Recent events tab, find the event your site sends when a lead form is submitted.
You should see: It is marked as a key event with the star icon next to it. Only key events can be imported as conversions.
If not: Click the star icon. Marking works from that moment on, not backward, and takes up to 24 hours to reach reports (GA4: key events). Which events deserve it is in GA4 key events for leads.
Check 6: Is the key event imported into Google Ads?
WhereGoogle AdsGoalsConversionsSummary
Do: Click + Create conversion action, select your GA4 property, select the lead event, click Select events, then Save and continue (Google Ads: conversions from GA4).
You should see: The new action in the conversion actions list. Data can take up to 24 hours to arrive, and nothing from before the import comes across.
If not: If the property is not offered, go back to check 4. If your account shows +New conversion action instead, choose Import, Google Analytics properties, Web and Continue, tick the key event and click Import and continue (web key events).
Careful: Every key event in the property appears in the list. That includes
session_start, view_item and five other events GA4 marks as key events once Enable Personalized Advertising is on, which it is by default when you link. Tick only the lead event.Check 7: Does the action count one conversion per click?
WhereGoogle AdsGoalsConversionsSummary
Do: Click the name of the imported action, then Edit Settings in the bottom right corner.
You should see: Count set to One. Google's guidance is "Every" for sales and "One" for leads (conversion action settings), so two form fills after one ad click count once.
If not: Set it to One and click Save. If GA4 gives conversion credit to Paid and organic channels, Count and the conversion window are managed in GA4 under Advertising > Conversion management instead (GA4 attribution settings).
Check 8: Is the import secondary to your uploads?
WhereGoogle AdsGoalsConversionsSummary
Do: Find the goal that holds the imported action and click Edit goal.
You should see: If you upload offline conversions, the action set to Secondary (observe only) under Conversion action optimization. Secondary actions report in All conversions and do not bid (primary and secondary actions). Google sets some GA4-based actions secondary itself, such as those created in the GA4 interface, "to prevent counting the same event twice for bidding".
If not: Select Secondary (observe only) and click Save. The uploads are your primary actions: the GA4 form fill and the uploaded lead are one person counted twice, and only the upload knows which leads became customers. If the GA4 import is your only lead action, leave it primary. I hold the same rule for calls. In a multi-location US medical practice's account, CallRail's native integration sent calls into several call conversion actions, all set to primary, next to a qualified-call upload I built, and the choice there was one primary path.
Careful: A custom goal that includes the action bids on it whether it is primary or secondary.
Check 9: Do conversions arrive from Google Analytics?
WhereGoogle AdsCampaigns
Do: A day after the import, click the segment icon and select Conversions, then Conversion source, and read the All conversions column.
If not: Only key events tied to Google Ads campaigns become conversions; key events from direct traffic or other campaigns are not created as conversions. If the row disagrees with GA4, Google Ads files a conversion under the click date and GA4 under the event date (data discrepancies); why Google Ads and GA4 conversions don't match covers the rest of the gap.
After the link works
GA4 now shows what ad visitors do on the site, and Google Ads can bid on what your uploads report. The step that pays is making those uploads carry the leads that became customers, which is the offline conversion tracking setup I build as part of marketing analytics.
Tags
how-to-link-ga4-to-google-adslink-ga4-to-google-adsgoogle-ads-import-ga4-conversionsga4-key-eventsauto-taggingsecondary-conversion-actions
Frequently asked questions
Should I link GA4 to Google Ads from GA4 or from Google Ads?
Either works. A link made in GA4 under Admin > Product links > Google Ads links also shows in Google Ads under Tools > Data manager, and the other way around. Linking from GA4 needs the Editor or Administrator role on the property plus administrative access in Google Ads.
Why is my imported GA4 conversion secondary in Google Ads?
Google sets an action secondary when it is created in the GA4 interface, or when the Google Ads account already has goals from an Analytics property, to prevent counting the same event twice for bidding. Only Google Ads can change that setting. If you also upload offline conversions, leave the GA4 import secondary and let the uploaded leads bid.
Why is my GA4 key event not showing up in Google Ads?
Linking alone does not create conversions: you have to import the key event under Goals > Conversions > Summary. After that, data takes up to 24 hours, nothing from before the import comes across, and only key events from Google Ads campaigns become conversions.
How long does Google Ads data take to show in GA4 after linking?
Up to 48 hours. If it is still missing after that, check that auto-tagging is on and that the gclid survives every redirect to your landing page.