Google Tag Assistant: Check Your Conversion Tags Fire

Google Tag Assistant, at tagassistant.google.com, is Google's tool for checking the tags on your site: you connect it to a page, click through, and it shows which Google tags loaded and which hits they sent. Below, I use it to confirm that the Google tag, a Google Ads conversion and a GA4 event fire when someone submits a lead form or books.

Start here

Connect and read the summary

Check 1: Connect Tag Assistant to your landing page

WhereTag AssistantAdd domain

Do: Open tagassistant.google.com, click Add domain, enter the page an ad sends people to, starting with https://, and click Connect. Google advises starting on a landing page, not the thank-you page.

You should see: Your site opens in a new window or tab with a debug parameter, _dbg, added to the end of the URL (connect Tag Assistant).

If not: Go to If Tag Assistant will not connect.

Careful: Install the Tag Assistant Chrome extension first. Without it, the debug window is a pop-up and a Google tag inside an iframe goes undetected.

Check 2: Is your Google tag on the page?

WhereTag AssistantSummary

Do: Back in the Tag Assistant tab, read the tag IDs it detected. If there are several, select one to see only its hits (find your way around Tag Assistant).

You should see: The IDs you expect, which look like Google's examples G-XXXXXXXXX and AW-XXXXXXXXX (tag IDs), or your Tag Manager container. No second copy: Google warns against multiple Google tags or containers on one page.

If not: Place the Google tag or the container snippet high in the head of the page. Pages Tag Assistant finds untagged are added as suggestions to your Tag coverage summary.

Fire a test lead and read the hits

Check 3: Submit a test lead from the landing page

Do: From the connected page, click through to your form or booking widget and submit it with an obvious test name, so nobody calls it back.

You should see: New numbered events in the left column, in the order they fired, grouped under the page where they happened. A new page group appears at the top when you reach a thank-you page that has the Google tag (event list).

If not: If no event appears when you submit, nothing on the page tells the Google tag about the submit. With Tag Manager, go to check 7; with gtag.js, make sure the event snippet runs on the conversion page.

Careful: Tags inside an iframe, such as an embedded booking widget, can only be debugged with the extension, and Google says not to fire conversion tracking from within an iframe. The Calendly manual covers that case.

Check 4: Did the Google Ads conversion fire?

Do: Select your Google Ads tag ID, click the event for your submit, and open its hit under Hits Sent in the Output section. Clicking the hit shows the parameters it sent (hits detail).

You should see: A hit on that event whose conversion ID and label match the action in Google Ads. Google's check here is that the labels in your tag match the labels in your account; this is where to find them.

If not: No hit means the conversion tag is not set to run on this event: fix its trigger or snippet. With a wrong label, copy it again from the conversion action.

Careful: With consent mode, accept your banner before testing. The Consent tab in Output shows the On-page Default and On-page Update columns, and an empty tab means consent mode is not implemented on the page.

Check 5: Did the GA4 event fire?

Do: Select your GA4 tag ID and click the same submit event.

You should see: A Google Analytics Hit under Hits Sent named after your lead event, as in Google's example. Google's recommended event for someone who submits a form or a request for information is generate_lead; which events to mark as key events is a separate decision.

If not: No hit means the GA4 event tag or call does not run on the submit. Fix its trigger, and spell the event name exactly as GA4 should receive it.

Check 6: Does GA4 receive the event?

WhereGA4AdminData displayDebugView

Do: Keep the session connected and open DebugView. Connecting through Tag Assistant turns on debug mode for your browser.

You should see: Your event in the Seconds stream, which lists events from the last 60 seconds. Click it to read its parameters.

If not: If you use consent mode and analytics cookies were not accepted, events do not show in debug mode. Accept them in your banner and submit again.

If your tags run in Google Tag Manager

Check 7: Do the tags fire in preview mode?

WhereGoogle Tag ManagerWorkspacePreview

Do: Click Preview, enter the landing page URL and click Connect. Back in the Tag Assistant tab, click Continue, then submit the test lead on your site (preview and debug).

You should see: The site shows Connected in the bottom right. On your submit event, the Tags tab shows the Google Ads conversion tag and the GA4 event tag fired, and the debug interface shows what triggered, or did not trigger, each tag. The Conversion Linker should fire on every page, as Google recommends.

If not: Open the tag that did not fire, correct its trigger, and preview again. A trigger can be too specific, such as a URL condition with http that never matches an https page.

Careful: Preview runs your unpublished draft. When it passes, click Submit and then Publish (publishing), or the live site keeps the old tags.

Confirm in Google Ads

Check 8: Does Google Ads mark the action verified?

WhereGoogle AdsGoalsSummary

Do: Under the Conversions dropdown, select All conversions. In Tracking status, hover a status of Unverified, Tag inactive or Needs attention, select Troubleshoot and then Continue. Connect to the landing page, submit the test lead and select Finish (Google Ads help).

You should see: The Results of troubleshooting page shows the action as verified. About 30 minutes later the account shows it as no recent conversions, and as Recording once a real conversion arrives. What each status means is in Google Ads conversion status.

If not: If the Tag Assistant badge gave no feedback after you submitted, select I thought I already triggered it to see the failed result and Google's recommendation.

Careful: Close the session with Finish; a closed browser window leaves it to time out. With Tag Manager, you may first need to select Debug live version in the Tag Assistant window.

If Tag Assistant will not connect

Without the extension, the debug window opens as a pop-up (Tag Assistant help), and Chrome blocks pop-ups by default. If the address bar shows Pop-up blocked, click it and select Always allow pop-ups and redirects from [site] > Done (Chrome help), or install the extension so the window opens as a tab.

Google's other connection fixes: try a page that has the Google tag; click Retry if the tag loads after Tag Assistant tries to connect; if the debug parameter breaks the page, edit the domain and deselect Include debug signal in the URL; avoid URLs with several redirects; turn off ad blockers; give the extension permission to read and change site data. AMP pages are not supported. If a consent banner keeps the tag from loading and Tag Assistant shows Could not connect, accept the banner and it should connect.

To get help, use Export session from the overflow menu, and know that any personal information your tags send is exported with it.

After the tags fire

When all three fire on a test lead, the browser side of tracking works. Tag Assistant cannot show which of those leads turned into a booked appointment or a sale, because that outcome lives in your phone system or CRM, not in a tag. Sending those outcomes back to Google Ads is the work of closed-loop measurement.

Frequently asked questions

Do I need the Tag Assistant Chrome extension?

Not to connect: tagassistant.google.com works on its own. Google recommends the extension because with it the debug window opens in a new tab instead of a pop-up, a Google tag inside an iframe is detected, and pop-ups or new tabs opened from your page can be debugged in the same session.

Why does Tag Assistant say could not connect?

Google's list of causes includes these: the page has no Google tag, the tag loads after Tag Assistant tries to connect (click Retry), the debug parameter breaks the page, several redirects stop the debug window from loading, an ad blocker or consent tool blocks the tag, or the page is AMP. If a cookie banner blocked the tag, accepting it on your site should let Tag Assistant connect.

Why is Google Tag Manager preview not working?

Preview connects through Tag Assistant, so the same causes apply. The debug interface also appears only in the browser that started preview or for people you share it with, and if the debug parameter breaks your site, uncheck "Include debug signal in the URL" before you click Connect.

How long after a Tag Assistant test does Google Ads show the conversion as verified?

After a troubleshooting session started from Google Ads, the actions it verified update in the account in about 30 minutes. Google says other tag fixes can take 24 to 48 hours to show in the tracking status.