Google Ads can only optimise towards the conversions it can see, and every year it sees fewer of them. Cookie banners, browser privacy features and people switching between phone and laptop all break the trail between an ad click and the enquiry or sale that followed. The conversion still happened. Google just cannot connect it to the ad.
Enhanced conversions are Google’s answer to that gap, and for most businesses running Google Ads they are one of the most worthwhile tracking jobs you can do. Here is what they are, how they work and what to check.
What enhanced conversions do
When someone converts on your website, they usually give you something about themselves: an email address in an enquiry form, a phone number at checkout, a name and address on an order. Enhanced conversions take those details, hash them on your site with SHA-256 (a one-way scramble, so the raw details never leave in readable form), and send the hashed values to Google alongside the conversion.
Google then compares the hashed values with the signed-in Google accounts it already knows about. If there is a match, it can link the conversion to the ad click that led to it, even when the cookie that would normally make that link has gone. The result is more of your real conversions reported in Google Ads, and better data for Smart Bidding to learn from.
Two flavours: web and leads
There are two versions, and which you need depends on how your business makes money.
- Enhanced conversions for web improve the conversions that happen on your site: purchases, form submissions, bookings. The customer details are captured on the conversion page and sent with the conversion tag.
- Enhanced conversions for leads are for businesses where the real sale happens later, offline. The hashed email or phone number is captured when the lead comes in, and when that lead later becomes a customer you upload the outcome to Google Ads. Google matches it back to the original click, so you can bid towards leads that turn into revenue rather than every form fill.
For an e-commerce site, the web version is usually the place to start. For a service business that closes work by phone or in person, enhanced conversions for leads is where the bigger gains tend to be, because it teaches Google which enquiries were worth having.
How they are set up
You can switch enhanced conversions on in three main ways: through Google Tag Manager, through the Google tag (gtag.js) directly on the site, or through the Google Ads API for businesses that send conversions from their own systems. In each case you first accept the customer data terms in Google Ads, then tell the tag where to find the customer details on the conversion page.
That second step is where most setups go wrong. The tag needs the email or phone number at the moment the conversion fires. If your thank-you page does not have them, or the form submits in a way the tag cannot read, the conversion goes through with no customer data attached and nothing is matched. Tag Manager can pick the details out of the page automatically, but on many sites it is more reliable to make them available on purpose, so you know exactly what is being sent.
Enhanced conversions also respect consent. If a visitor has declined advertising data in your cookie banner, the customer data is not sent. That is how it should be, and it is another reason to make sure consent mode v2 is working first.
How to tell if they are working
- Check the diagnostics in Google Ads. Each conversion action has an enhanced conversions status. Give it a few days after setup, then look for a healthy status and a match rate rather than warnings about missing data.
- Test a real conversion. Submit your own form or place a test order with Tag Assistant running, and check that the conversion event carries user-provided data.
- Look at the trend, not the day. Reported conversions should rise compared with the same period before, because Google is now recovering ones it previously missed. A big jump on day one usually means something is double counting.
- Watch for duplicate tags. If the same conversion is tracked twice, once with enhanced data and once without, you will inflate your numbers and confuse your bidding.
Worth the effort
Enhanced conversions do not change what happens on your site, and visitors never see them. What they change is how much of your real performance Google Ads can see, and therefore how well it spends your budget. On accounts where conversions have been drifting down while enquiries feel steady, they are often the missing piece.
Setting them up properly, alongside GA4 and consent mode, is part of our conversion tracking and GA4 work, and it is one of the first things we check when we take on Google Ads management. If you are not sure whether yours are on, or working, get in touch and we will look.