Google Ads conversion tracking setup with GA4: a step-by-step guide

A complete Google Ads conversion tracking setup has six parts: one Google tag on every page, GA4 linked to Google Ads with auto-tagging on, your key actions marked as key events, conversion actions created in Google Ads, consent mode v2 sending consent signals, and enhanced conversions sending hashed customer data. Miss one and Smart Bidding optimises on incomplete data.

Every automated bid strategy, from Maximise conversions to target CPA, learns from the conversions you report. If a form fill is counted twice or a newsletter sign-up is treated like a sales enquiry, Google will spend your budget finding more of the wrong thing. This guide walks through the setup in the current Google Ads and GA4 interfaces, using Google’s own help documentation. It is the setup we complete before launching any campaign under our Google Ads management service.

Key takeaways

• Decide what counts as a conversion before touching any tag. Only real business outcomes should be primary conversions used for bidding.
• Use one Google tag across the site, link GA4 and Google Ads, and keep auto-tagging on so the click ID (GCLID) reaches your site.
• Use Google Ads conversion actions for bidding and GA4 key events for analysis. If you import GA4 key events, keep them secondary or remove the duplicate tag conversion, so nothing is counted twice.
• Consent mode v2 (ad_storage, analytics_storage, ad_user_data, ad_personalization) is required for traffic from the EEA, the UK and Switzerland, and is good practice everywhere.
• Turn on enhanced conversions, and for lead businesses, import offline outcomes from your CRM so bidding learns which leads became customers.

Step 0: plan what you will track

Write down every action that matters, decide whether it is a primary conversion (used for bidding) or secondary (observed only), and give it a value. A simple plan for a service business looks like this:

Click events such as “tapped WhatsApp” record intent, not outcomes, so start them as secondary.

Step 1: install the Google tag on every page

The Google tag (gtag.js) is the single tag that serves both Google Ads and GA4. It must load on every page of the site, not just the thank-you page. You have three ways to install it:

• Google Tag Manager (GTM). The most flexible option and the one we recommend for most sites, because you can add events, consent rules and other platforms’ tags without editing code each time.
• Directly in the site code. Paste the tag into the <head> of every page. Fine for simple sites with a developer on hand.
• A CMS integration. On WordPress, Google’s Site Kit plugin or a reputable tag plugin can place the tag for you. If your site needs a cleaner setup, our WordPress development team handles this as part of a build.

Use one method only. Two copies of the same tag, one hard-coded and one in GTM, is one of the most common causes of double-counted conversions.

Step 2: link GA4 and Google Ads, and keep auto-tagging on

In GA4, go to Admin, then under Product links open Google Ads links, click Link, choose your Google Ads account, and confirm. During setup, leave personalised advertising on if you plan to use GA4 audiences for remarketing, and enable auto-tagging when offered.

Auto-tagging adds a GCLID parameter to every ad click URL. Google’s help on creating conversions from GA4 events notes that your site must preserve the GCLID for conversions to be attributed, so check that redirects or plugins are not stripping it. You need at least the Marketer role in GA4 and admin access in Google Ads for the import steps.

Step 3: mark your key actions as key events in GA4

GA4 renamed “conversions” to key events. A key event is any GA4 event you flag as important. To mark one, go to Admin, then under Data display open Events, find the event and click the star icon. Google’s key events documentation adds a few rules worth knowing:

• An event must have fired at least once before it appears in the list. For a new event, use Create event and switch on Mark as key event.
• Standard GA4 properties allow up to 30 key events.
• Marking only applies from that moment. Historical data is not reprocessed, and standard reports can take up to 24 hours to update.

For lead forms, GA4’s recommended event is generate_lead. If your site only fires a generic form_submit for every form, create a filtered event (for example, form_submit where the page location contains /thank-you/) so that a newsletter sign-up does not count as an enquiry.

Step 4: create conversion actions in Google Ads

Google rebuilt the conversion setup flow around data sources. Following the current web conversions setup guide:

1. In Google Ads, open the Goals menu and select Summary.
2. Select + Create conversion action, then Edit data sources for conversions on a website.
3. Enter your domain and select Scan. Google checks for the Google tag and any linked GA4 property.
4. Choose a category that matches the action, such as Submit lead form, Contact or Purchase.
5. Define the conversion. Either use the Google tag (with one of three methods below) or select GA4 events.
6. Set the action as Primary or Secondary. Only primary actions feed Smart Bidding.
7. Review Conversion settings: value, count, click-through window, engaged-view and view-through windows, and attribution.
8. Finish setup, turn on enhanced conversions when prompted, and select Agree and finish.

The three Google tag methods are:

• Automatically without code. Define the conversion as a page load or form submission on a URL that “is”, “contains” or “starts with” a value. Good for thank-you pages.
• Manually using code. Google gives you an event snippet to fire on the conversion. Needed for single-page forms that do not change URL, or dynamic values.
• Use Google Tag Manager. Google can push the suggested tags into a GTM container for you; you then set triggers and publish.

Count setting: “One” or “Every”?

For leads, set count to One. If someone submits your form three times after one click, that is one lead. For purchases, use Every, because each order is real revenue.

Google Ads tag or GA4 import?

Both work. They count differently, and you should know how before choosing.

Google’s GA4 import documentation explains these differences and why imported GA4 conversions start as secondary. The practical rule: pick one source of truth per action for bidding. If the Google Ads tag tracks your form as primary, leave the GA4 import of the same form as secondary.

Step 5: set up consent mode v2

Consent mode passes each visitor’s cookie choices to Google tags so they behave accordingly. It does not show a banner itself; it works with your consent banner or consent management platform (CMP). There are four consent types that matter for ads:

• ad_storage: cookies for advertising.
• analytics_storage: cookies for analytics.
• ad_user_data: consent to send user data to Google for advertising.
• ad_personalization: consent for personalised advertising and remarketing.

Google’s consent setup guide for developers shows the pattern: set defaults before any tag fires, then update when the visitor chooses.

gtag('consent', 'default', {
  'ad_storage': 'denied',
  'ad_user_data': 'denied',
  'ad_personalization': 'denied',
  'analytics_storage': 'denied',
  'wait_for_update': 500
});

// after the visitor accepts in your banner
gtag('consent', 'update', {
  'ad_storage': 'granted',
  'ad_user_data': 'granted',
  'ad_personalization': 'granted',
  'analytics_storage': 'granted'
});

Defaults can be scoped by region with a region parameter, so you can deny by default in Europe and grant by default elsewhere where your legal advice allows.

Basic or advanced consent mode?

Google’s consent mode overview describes two modes. In basic mode, Google tags do not load until the visitor responds to the banner, and nothing is sent if they decline. In advanced mode, tags load with consent denied and send cookieless pings, which lets Google build an advertiser-specific conversion model to fill gaps. Advanced mode recovers more measurement; basic mode is the more conservative choice. Consent mode impact reporting appears after at least seven full days.

Who must use it?

Google requires consent signals for traffic from the European Economic Area, the UK and Switzerland. Its EEA consent mode update says advertisers who want to keep using measurement, personalisation and remarketing for EEA users must collect consent and pass it through ad_user_data and ad_personalization. If your site gets visitors from the UK or Europe, this is not optional.

For Indian businesses, the Digital Personal Data Protection Act, 2023 and the DPDP Rules notified in November 2025 introduce consent notice obligations over an 18-month phased compliance period. Get legal advice on your notice and consent wording; consent mode is the technical layer that carries those choices to Google.

Step 6: turn on enhanced conversions for web

Enhanced conversions send a hashed (SHA-256) version of details the customer already typed into your form, such as email or phone number, alongside the conversion. Google matches it to signed-in Google accounts, which recovers conversions that cookies miss. To set it up with the Google tag, following Google’s enhanced conversions for web guide:

1. Go to Goals, then Settings, and expand Enhanced conversions.
2. Check Turn on enhanced conversions and Agree to the customer data terms.
3. Choose Google tag as the method.
4. In Tag details, choose how data is collected: Automatically detect user-provided data, Specify CSS selectors or Javascript variables, or Add a code snippet to your website. The code snippet is the most reliable for custom forms.
5. Save.

To validate, submit a test form with Chrome developer tools open, filter the Network tab for “google”, open the conversion request and check the payload for an em parameter starting with tv.1~em followed by a long hashed string. If you see only tv.1~em, the data was empty when the conversion fired. The Diagnostics report appears about 72 hours after setup, and impact results after about 30 days. Remember that when ad_user_data is denied, enhanced conversion data is not sent for that visitor.

Step 7: import offline outcomes with enhanced conversions for leads

For lead businesses, the form fill is not the sale. A clinic wants booked appointments, a builder wants site visits, a B2B firm wants qualified enquiries. Google’s enhanced conversions for leads is the recommended way to tell Google which leads turned into business:

1. The visitor submits your form; the Google tag sends hashed lead details.
2. You store the lead, with its GCLID if available, in your CRM.
3. When the lead becomes qualified or buys, you upload that outcome with the same hashed details.
4. Google matches it to the original ad click and reports it as a conversion.

Two 2026 changes matter here. Google is combining enhanced conversions for web and for leads into a single setting, with existing users migrated automatically. And from 15 June 2026, offline conversion and enhanced conversions for leads uploads moved to the Data Manager API and are blocked in the Google Ads API, so use Data Manager or a connector that supports it. Once enough qualified-lead conversions flow in, make that action primary and the raw form fill secondary. This is the single biggest lever for lead quality, and it matters just as much when you compare platforms, as covered in our guide to Google Ads vs Meta Ads for lead generation.

Step 8: test your Google Ads conversion tracking setup before spending

Use this checklist on every new setup:

1. Open your site with Google Tag Assistant connected and confirm the Google tag fires once per page.
2. Submit a real test enquiry and confirm the conversion tag fires once, on the right page or event.
3. Check GA4 Realtime or DebugView for the key event.
4. Confirm the landing page URL still contains the gclid parameter after any redirects.
5. Test the consent banner: decline, then accept, and confirm consent states update in Tag Assistant.
6. Validate enhanced conversions with the em parameter check above.
7. In Google Ads, open Goals, then Summary, and check each action’s Status column over the next 24 to 48 hours.
8. Check that only real business outcomes are marked Primary.
9. Compare the week’s Google Ads conversions with leads in your inbox or CRM. They will not match exactly, but large gaps mean something is broken.

Common problems and fixes

If forms sit inside pop-ups or third-party widgets, a cleaner page often fixes both tracking and conversion rate; our landing page design work builds tracking in from the start. Once tracking is reliable, our Google Ads cost guide for India helps turn cost per conversion into a budget.

Frequently asked questions

Should I use the Google Ads tag or import conversions from GA4?

Either can work. The Google Ads tag reports conversions against the click date and is the usual choice for bidding. GA4 imports report against the conversion date and are useful when you want one source for all channels. Do not use both as primary for the same action, or every lead is counted twice and Smart Bidding overvalues your campaigns.

What is the difference between a GA4 key event and a Google Ads conversion?

A key event is a GA4 event you have flagged as important for analysis. A Google Ads conversion is an action that Google Ads counts and can use for bidding. You can create Google Ads conversions from GA4 key events, but they are managed separately: primary or secondary status and goal categories are set inside Google Ads, not GA4.

Is consent mode v2 required for Indian websites?

Google requires consent mode or another approved consent signal for traffic from the EEA, the UK and Switzerland. If your Indian website receives visitors from those regions and you use Google Ads measurement or remarketing, you need it. For Indian visitors, India’s DPDP Act and Rules set consent notice duties that phase in through 2027, so setting up consent mode now is sensible.

Do enhanced conversions share my customers’ data with Google?

Enhanced conversions send a one-way SHA-256 hash of details such as email or phone, not the plain text. Google matches the hash to signed-in accounts that interacted with your ads and reports conversions in aggregate. You must accept Google’s customer data terms and disclose this use in your privacy policy, and the data is not sent for visitors who deny ad_user_data consent.

How long after setup will conversions appear in Google Ads?

Tag-based conversions usually show within a few hours of the first conversion, and the status column updates within a day or two. Imported GA4 key events can take up to 24 hours, and links or new key events can take 24 to 48 hours before they appear as import options. Enhanced conversions diagnostics appear after about 72 hours.

Unsure whether your current tracking can be trusted? We audit your Google tag, GA4 key events, conversion actions, consent mode and enhanced conversions, and send a written fix list. Learn more about our Google Ads management or request a free audit.

Sources

• support.google.com/google-ads/answer/16560108
• support.google.com/google-ads/answer/2375435
• support.google.com/analytics/answer/13128484
• support.google.com/google-ads/answer/10000067
• developers.google.com/tag-platform/security/guides/consent
• support.google.com/google-ads/answer/13695607
• support.google.com/google-ads/answer/13258081
• support.google.com/google-ads/answer/15713840