Your Google Ads account is probably missing conversions. Not because your tag is broken, but because browsers limit cookies, people switch devices between clicking and buying, and some visitors decline tracking. Each lost conversion makes Smart Bidding a little less sure about which clicks are worth paying for.
Enhanced conversions is Google's main fix for that gap. It adds hashed first-party data, such as the email address a customer types at checkout, to your conversion tag so Google can match the conversion to a signed-in Google account even when the cookie trail has gone cold. A version for leads does the same for sales that close offline.
This guide explains why conversions disappear, how enhanced conversions works, the difference between the web and leads versions, how to set each one up through the Google tag, Google Tag Manager or the API, how consent fits in, and how to confirm the data is flowing.
Where Google Ads conversions get lost
Standard conversion tracking relies on a click identifier stored in a first-party cookie when someone clicks your ad. When the same browser later loads your thank-you page, the tag reads that cookie and reports the conversion. The chain breaks in predictable places:
- Cookie restrictions. Some browsers limit how long cookies set by scripts survive, so a customer who returns after a week may no longer carry the click identifier.
- Device switching. Someone clicks an ad on their phone at lunch and buys on a laptop that evening. The laptop never saw the click.
- Consent choices. Where users decline advertising cookies, tags behave differently and some conversions cannot be observed directly.
- Offline closes. A lead form is submitted online but the sale happens on a phone call two weeks later.
Our guide to cookieless tracking covers the browser side in more depth. The practical effect is the same in every case: conversions happen, but Google Ads cannot connect them to the click, so it under-reports results and bids with less information.
How hashed first-party data closes the gap
Enhanced conversions works by collecting customer data your site already handles at the point of conversion: email address, phone number, and name with address. The Google tag normalises it (lowercasing and trimming, for example) and hashes it with SHA-256, a one-way algorithm, before sending it with the conversion. Google compares the hashed values with hashed data from signed-in Google accounts. When it finds a match to an account that interacted with your ad, it can attribute the conversion even without the cookie.
Three points are worth stressing to anyone nervous about the approach:
- The data is hashed in the browser before leaving it.
- It is used for matching and measurement under Google's customer data terms, which you must accept in the account.
- It only helps where the customer has a Google account Google can match to; it is a recovery mechanism, not a guarantee.
What gets sent, field by field
| Field | Normalisation before hashing | Priority |
|---|---|---|
| Lowercase, trim whitespace; for gmail.com/googlemail.com, remove dots before @ | Highest; send whenever you have it | |
| Phone number | E.164 format with country code, for example +12025550123 | High; useful backup |
| First and last name | Lowercase, trim; remove punctuation | Only useful with address fields |
| Street address, city, region, postcode, country | Standardised; country as two-letter code | Supplements name for matching |
Enhanced conversions for web versus enhanced conversions for leads
The two versions share the hashing idea but solve different problems.
| Enhanced conversions for web | Enhanced conversions for leads | |
|---|---|---|
| Problem it solves | Online conversions lost to cookie and device gaps | Offline sales from online leads that cannot be tied back to clicks |
| When data is captured | At the conversion itself (checkout, sign-up) | At lead submission, then again when the deal closes |
| How the conversion reaches Google | Live, with the conversion tag | Uploaded later from your CRM, matched on hashed email or phone |
| Click ID needed? | No (but used when available) | No; that is the main advantage over classic offline imports |
| Typical users | Ecommerce, online subscriptions, app sign-ups | B2B, home services, education, finance, healthcare lead generation |
Google positions the leads version as the successor to click-ID based imports:
“Enhanced conversions for leads is an upgraded version of offline conversion import that uses user-provided data”
— Google Ads Help, About enhanced conversions for leads
The older method still exists and depends on storing the click ID with each lead:
“Google Ads provides you with unique IDs, called Google Click ID (GCLID), for every click.”
— Google Ads Help, About offline conversion imports
If you already pass GCLIDs into your CRM reliably, you can keep doing so. If GCLIDs keep going missing between form and CRM, the leads version is usually simpler. Our offline conversion tracking guide walks through both pipelines.
Setting up enhanced conversions for web
Before touching any tags, switch the feature on and accept the terms.
- In Google Ads, go to Goals > Conversions > Settings and open the Enhanced conversions for web section.
- Turn it on and accept the customer data terms.
- Choose your method: Google tag, Google Tag Manager or Google Ads API. Pick the one that matches how your conversion tag is installed today.
- Run the URL check if offered, which looks for your tag and suggests whether automatic detection will work.
- Configure the data collection (below), publish, then complete a test conversion.
Choosing between automatic, CSS selector and code-based collection
| Method | How it finds the data | Reliability | Best for |
|---|---|---|---|
| Automatic detection | The tag scans the page for email/phone fields | Lowest; can miss fields or break with redesigns | Quick start on simple sites |
| CSS selectors | You point the tag at specific page elements | Medium; breaks if element IDs change | Sites where the data is visible on the confirmation page |
| Code / data layer | Your site pushes the values into the data layer or tag config | Highest | Ecommerce platforms and any site with developer access |
Code-based collection is the robust option. In Google Tag Manager, create a User-Provided Data variable that reads values from data layer variables, then reference that variable in the Google Ads conversion tag's "Include user-provided data from your website" setting. Our explainer on the data layer shows how to push checkout fields into it, and our Google Tag Manager guide covers tag and trigger basics.
Here is a simplified data layer push your developer might add on the order confirmation page:
dataLayer.push({
event: 'purchase',
user_data: {
email: 'customer@example.com',
phone_number: '+447700900123',
address: { first_name: 'Sam', last_name: 'Lee', postal_code: 'SW1A 1AA', country: 'GB' }
}
});The Google tag hashes the values before sending. Some setups hash server-side first and pass already-hashed values; follow the formatting rules for whichever route you choose.
Platform shortcuts
Several ecommerce platforms and their official Google integrations can switch on enhanced conversions without custom code. If you use one, check its Google channel settings before building anything yourself, and avoid running a platform integration and a manual tag for the same conversion, which double counts.
Setting up enhanced conversions for leads
The leads version has two halves: capture at form submission and upload at close.
- Turn it on under Goals > Conversions > Settings > Enhanced conversions for leads and accept the terms.
- Capture on the form. Configure the Google tag (directly or in GTM) to collect the email and, ideally, phone from the lead form at submission. This sends a hashed record linked to the ad click.
- Store the same email and phone in your CRM with each lead, unhashed, as you normally would.
- Create an offline conversion action for each stage that matters, such as "Qualified lead" and "Closed deal", with sensible values.
- Upload closed stages from your CRM, including the email or phone, conversion time and value. Use a CRM integration, Google Ads Data Manager, scheduled uploads or the API.
- Check the upload diagnostics for match and error counts after each upload.
Uploading pipeline stages rather than just form fills lets Smart Bidding optimise for leads that become customers. Pair this with lead scoring so that values reflect lead quality, and store campaign data in the CRM as described in our guide to UTM data in your CRM.
Consent, privacy notices and the EEA
Enhanced conversions processes personal data, even though it is hashed. Three obligations apply in most jurisdictions:
- Disclosure. Your privacy policy should say that you share customer data with advertising partners for measurement.
- Consent where required. In the EEA and UK, Google expects consent signals for ad user data. With consent mode, the
ad_user_dataparameter controls whether user-provided data can be sent. - Data minimisation. Send only the fields Google uses for matching. Do not add order notes, health information or anything sensitive.
“Consent mode allows web and app developers to adjust tag and app SDK behavior based on user consent choices.”
— Google Tag Platform, Consent mode overview
Our guides to consent mode and marketing privacy laws cover the wider requirements. Regulated advertisers, particularly in healthcare, should check whether conversion pages could reveal sensitive information before enabling any user-provided data collection.
Proving that enhanced conversions is working
Enabling the setting is not the same as receiving data. Verify at three levels.
1. Tag level: is data being sent?
Use Tag Assistant or your browser's developer tools on a test conversion. In the network request for the Google Ads conversion, look for user data parameters carrying hashed values. In Tag Manager preview, confirm the User-Provided Data variable resolves to real values rather than "undefined".
2. Account level: is Google receiving it?
Open the conversion action and its Diagnostics view. After real conversions have flowed for a few days, it reports whether enhanced conversions are being recorded, what share of conversions include user-provided data, and any problems such as missing fields or formatting errors.
3. Business level: is it adding conversions?
Compare reported conversions with your own records (orders in your shop platform or closed deals in your CRM) for equal periods before and after. You are looking for the reported share to move closer to reality.
Worked example: reading the before and after (hypothetical numbers)
| Period (28 days) | Orders in shop platform attributed to Google Ads by UTM | Conversions reported in Google Ads | Coverage |
|---|---|---|---|
| Before enhanced conversions | 410 | 322 | 79% |
| After enhanced conversions | 405 | 366 | 90% |
In this example, Google Ads reports 44 more conversions in a similar month without any change in real orders. Smart Bidding now has more data to learn from, and the reported cost per acquisition drops from what was an overstated figure. The comparison is rough – UTM attribution and Google's attribution model will never agree exactly – but the direction is what you are checking.
Problems the diagnostics commonly flag
- Email captured on the form page but not available on the confirmation page (fix by storing it in the data layer or session before redirect).
- Phone numbers without country codes.
- Multiple tags firing for one conversion, one with and one without user data.
- Consent banner blocking the tag before the user has chosen.
How enhanced conversions changes bidding and reporting
Once recovered conversions flow, Smart Bidding uses them automatically. Expect reported CPA to fall and ROAS to rise as previously invisible conversions appear. Re-check targets after a few weeks: a target CPA set when the account under-reported may now be too loose. If you report to stakeholders, annotate the date you switched on enhanced conversions so the step change is not mistaken for a performance jump. Our Google Ads conversion tracking guide covers the base setup if you are starting from scratch, and our guide to profit-based bidding explains what values to send once the counting is right.
Questions advertisers ask about enhanced conversions
Is enhanced conversions the same as server-side tagging?
No. Enhanced conversions adds hashed customer data to a conversion so Google can match it to a signed-in user. Server-side tagging changes where your tags run. You can use them together: a server-side Google tag container can send enhanced conversion data, but neither requires the other.
Does enhanced conversions send personal data to Google in plain text?
The Google tag normalises and hashes the data with SHA-256 before it is sent from the browser. Google uses the hashed values for matching. You are still processing personal data, so your privacy notice and consent setup need to cover it.
How long before I see results?
The diagnostics usually update within a few days of the first tagged conversions. Measurable changes in reported conversions take longer to judge, because you need enough volume to compare before and after. Give it at least two to four weeks.
Can I use enhanced conversions for leads if my CRM does not store the GCLID?
Yes, that is one of its main advantages. It matches offline conversions using the hashed email or phone captured at form submission, so you do not need to pass a click ID through your forms and CRM. You still need to upload the conversions from your CRM, manually or through a connector.
Will enhanced conversions fix low conversion volume?
It recovers conversions that already happen but go unmeasured. It does not create new ones. If your campaigns have very few conversions, you still need to look at targeting, landing pages and offer, alongside better measurement.
Do I need to change my bidding after enabling it?
Usually not. Smart Bidding starts using the recovered conversions automatically. If reported conversions rise noticeably, review target CPA or ROAS values after a few weeks, because the targets were set against under-reported data.
Switching on enhanced conversions in your account this week
Pick your highest-value conversion action, enable enhanced conversions for web or leads, and set it up with the data layer method if you have developer time or automatic detection if you need a quick start. Check the diagnostics after a few days and compare against your own order or CRM records after a month. If you also review your Google Ads recommendations, an "upgrade your conversion tracking" suggestion usually points to exactly this feature.
If your tracking spans several tools and you want it done once, properly, our PPC management team sets up enhanced conversions, consent mode and CRM imports together. Request a free quote to get started.
Further reading on enhanced conversions
- Profit-Based Bidding: Optimise Ads for Margin, Not Just Revenue
- Connected TV Advertising for Small and Mid-Sized Brands
- Podcast and Audio Advertising: Buying Ads That Convert
Sources for this enhanced conversions guide
- About enhanced conversions – Google Ads Help
- About enhanced conversions for leads – Google Ads Help
- About offline conversion imports – Google Ads Help
- Consent mode overview – Google Tag Platform
- Consent mode reference – Google Ads Help
- About conversion measurement – Google Ads Help
- Set up offline conversion imports using GCLID – Google Ads Help
- About Smart Bidding – Google Ads Help
