GA4 Conversion Tracking with Google Tag Manager, Step by Step

To track conversions in GA4 with Google Tag Manager, add a Google tag that loads on every page, then add a GA4 Event tag that fires when the conversion happens. Test both in Preview mode and publish. Finally, mark the event as a key event in GA4. If you run Google Ads, you can then import that key event as a conversion.

Key facts (as of October 2026)

• GA4 calls important actions key events. Google Ads can create conversions from them (Analytics Help).
• You can mark up to 30 events as key events in a standard property, or 50 in Analytics 360 (Analytics Help).
• Marking a key event doesn’t change historic data. Allow up to 24 hours for standard reports (Analytics Help).
• Use the Google tag (gtag.js) or Google Tag Manager, not both. Using both “will double count certain events” (Google Analytics developer docs).

What do you need before you start?

Google lists these prerequisites (Tag Manager Help):

• A Google Analytics 4 account and property.
• A web data stream for your website.
• A Tag Manager container installed on your site.
• Access to that container, and the Editor role or higher in the Google Analytics account.

You also need to decide what counts as a conversion. Pick one action that matters to the business, such as a completed contact form, a newsletter signup, or a purchase. Start with one. Adding more is easy once the first works.

Find your measurement ID

In GA4, go to Admin > Data collection and modification > Data streams, select the Web tab, and click your stream. The measurement ID is in the first row. It starts with “G-” followed by letters and numbers (Analytics Help).

Step 1: Add the Google tag in Tag Manager

The Google tag loads GA4 on every page. Skip this step if your container already has one for this GA4 property.

1. Go to tagmanager.google.com and open your container.
2. In Workspace, go to Tags and click New.
3. Name the tag, for example “Google tag – GA4”.
4. Click Tag Configuration and choose Google Tag.
5. Enter your tag ID. For GA4, this is the “G-” ID. Google lists G-XXXXXXXXX as one format of tag ID (Analytics Help).
6. Under Triggering, select Initialization - All Initialization Events.
7. Click Save.

These steps follow Google’s guide (Tag Manager Help). Don’t publish yet. You will test everything together in Step 3.

Step 2: Create a GA4 Event tag for the conversion

The Google tag sends page views. Your conversion needs its own event. Google’s process has two parts: a Google Analytics: GA4 Event tag, and a trigger that tells it when to fire (Tag Manager Help).

Create the tag

1. In Tags, click New and name it, for example “GA4 Event – generate_lead”.
2. Choose Google Analytics: GA4 Event as the tag type.
3. In Measurement ID, enter your “G-” ID.
4. In Event Name, enter the name of the event.
5. Optionally, add event parameters with extra details.

Use one of Google’s recommended event names when one fits. Google gives generate_lead, sign_up, and purchase as examples. For anything else, use a custom name such as signup_newsletter (Tag Manager Help). Pick lowercase names with underscores and keep them consistent. GA4 treats a differently spelled name as a different event.

Create the trigger

The trigger decides when the event fires. Google’s guide shows two common patterns (Tag Manager Help):

Pattern	When to use it	Example condition
Page View on a confirmation page	Your form or checkout sends people to a thank-you page	Page path equals your thank-you page, for example /thank-you
Click	The action is a button click with no new page	Click Text contains “Sign up for the newsletter”

A thank-you page trigger is the most reliable choice for small sites, because it fires only after a successful submission. A click trigger fires when someone clicks, even if the form then shows an error.

Attach the trigger to the tag and click Save.

Step 3: Test with Preview and Tag Assistant

Never publish untested tags. Tag Manager’s Preview mode shows exactly what fires (Tag Manager Help).

1. In your workspace, click Preview (top right). Google Tag Assistant opens in a new tab.
2. Enter your site’s URL and click Connect. Your site opens with a Connected badge in the bottom right.
3. Browse to the page where the conversion happens and complete it, for example by submitting the form with test details.
4. Go back to the Tag Assistant tab. Check that the Google tag fired on page load and the GA4 Event tag fired at the right moment, once.

The debug interface “shows detailed information about your tags, including how tags fired and what data is being processed” (Tag Manager Help). If a tag didn’t fire, check the trigger conditions. If it fired on the wrong pages, tighten them.

You can share a preview session with a colleague. In Tag Assistant, click More Actions, select Share, and copy the preview URL.

Check the event in DebugView

Tag Assistant tells you the tag fired. DebugView tells you GA4 received it.

1. In GA4, go to Admin > Data display > DebugView (Analytics Help).
2. With your preview session still open, repeat the conversion.
3. Look for your event name in the stream. Click it to see its parameters.

DebugView’s seconds stream shows the last 60 seconds of events, and the minutes stream covers the last 30 minutes. Events won’t appear if privacy controls or consent settings prevent Analytics cookies, so allow analytics cookies in your test browser (Analytics Help).

Step 4: Publish the container

1. In Tag Manager, click Submit (top right).
2. Choose Publish and Create Version.
3. Add a version name and description, for example “Add GA4 generate_lead event”.
4. Click Publish.

These are Google’s steps (Tag Manager Help). A clear version name makes it easy to roll back if something breaks later.

Step 5: Mark the event as a key event in GA4

An event is just an event until you tell GA4 it matters. Key events measure “actions that are important to your business” (Analytics Help).

1. In GA4, go to Admin > Data display > Events.
2. Find your event and click the star icon next to it.

If the event hasn’t arrived yet, you can still mark it ahead of time. GA4 then treats it as a key event once it is collected (Analytics Help).

Expect a delay. Key events appear in Realtime within minutes, but standard reports can take up to 24 hours. Marking doesn’t apply to past data, so your counts start from the day you mark it (Analytics Help).

Step 6: Import the key event into Google Ads (if you run ads)

If you advertise on Google Ads, you can use the GA4 key event as a Google Ads conversion.

Before you import, Google requires that you (Google Ads Help):

• Link your Google Analytics property and Google Ads account.
• Turn on auto-tagging in Google Ads.
• Have edit access to the Analytics property.

To import from Google Ads: click the Goals icon, open Conversions, click + New conversion action, choose Import, then Google Analytics properties and Web. Tick your key event and click Import and continue (Google Ads Help). You can also start the import from GA4 under Advertising > Conversion management (Google Ads Help).

After importing, open the conversion action in Google Ads and check whether it is a primary or secondary action. Primary actions are the ones Google Ads uses for bidding (Google Ads Help).

Don’t count the same action twice. If you already have a Google Ads conversion tag for the same form submission, importing the GA4 key event as well inflates your conversion count (Google Ads Help). Choose one source for each action.

What about consent mode?

If your site shows a cookie banner, your tags need to respect the visitor’s choice. Google’s consent mode “allows web and app developers to adjust tag and app SDK behavior based on user consent choices” (Google tag platform docs).

The two consent types most relevant here are:

• analytics_storage: storage, such as cookies, related to analytics.
• ad_storage: storage, such as cookies, related to advertising.

Consent mode also includes ad_user_data and ad_personalization for advertising. There are two ways to implement it (Google tag platform docs):

Mode	What happens before the visitor consents
Basic	Google tags don’t load and no data is sent until the visitor interacts with the banner
Advanced	Tags load with consent denied by default and send measurements without cookies; full data is sent once consent is granted

Most consent management platforms set this up for you. What your site legally needs depends on where you and your visitors are, which is a question for your own legal adviser, not for this guide.

Common mistakes

• Double tagging. A hard-coded gtag.js snippet plus a Google tag in Tag Manager for the same property. Google says to use one or the other (Google Analytics developer docs). Look in your page source, theme settings, and plugins for a second copy.
• Firing on the wrong page. A trigger like “Page path contains thank” can match blog posts too. Use an exact match.
• Counting form attempts. A click trigger on the submit button counts failed submissions. Prefer a confirmation page.
• Inconsistent event names. generate_lead and Generate_Lead show up as two events.
• Testing without consent. Your test events won’t show in DebugView if analytics cookies are denied.
• Forgetting to publish. Preview mode only affects your own browser. Nothing is live until you publish.
• Expecting old data. A new key event counts from the day you mark it.
• Counting twice in Google Ads. Don’t import a GA4 key event for an action that a Google Ads conversion tag already tracks.

Checklist

• One Google tag for the GA4 property, firing on Initialization - All Initialization Events
• No hard-coded gtag.js snippet for the same property
• GA4 Event tag with the correct measurement ID and a consistent event name
• Trigger fires once, only after a successful conversion
• Tags checked in Tag Assistant and the event seen in DebugView
• Container published with a descriptive version name
• Event marked as a key event in GA4
• (Google Ads) Accounts linked, auto-tagging on, key event imported, no duplicate conversion tag
• Consent banner and consent mode checked if you use one

To see which campaigns drive these key events, tag your links consistently. Our guide to a UTM parameters naming convention shows how.