Cookie restrictions, cross-device journeys, and privacy regulations mean 10-30% of Shopping conversions are invisible to standard tracking. A customer clicks your ad on their phone, researches on their tablet, and buys on their laptop three days later. Your conversion tag sees none of it. Or a Safari user clicks today but converts eight days later, past ITP's cookie expiry. That sale happened because of your ad, but your data says otherwise.
Enhanced conversions and Consent Mode v2 are Google's answer to this growing blind spot. Enhanced conversions use hashed customer data to reconnect conversions across devices and browsers. Consent Mode v2 ensures your tags comply with EU privacy law while still recovering modeled data from users who decline cookies. For EU advertisers, Consent Mode v2 has been mandatory since March 2024.
This guide covers how both technologies work, why you need them together, and how to implement them step by step for your Shopping campaigns.
The Cookie Problem
Standard Google Ads conversion tracking relies on cookies to connect ad clicks to purchases. That model is breaking down from multiple directions at once.
Safari ITP caps third-party cookies entirely and limits first-party cookies to 7 days for link-decorated traffic. A user who clicks your Shopping ad in Safari and returns 8 days later to buy is invisible to your conversion tag. Given Safari's market share on mobile, this alone creates a significant data gap.
Firefox ETP blocks third-party cookies by default. Chrome has signaled the same direction for years, and while the exact timeline has shifted, the trajectory is clear: third-party cookies are going away across all major browsers.
Ad blockers add another layer. Roughly 25-30% of users run some form of ad or tracking blocker. These tools can prevent conversion tags from firing entirely, meaning a real purchase never gets recorded.
Cross-device journeys are the final piece. A user clicks your Shopping ad on mobile during their commute, then completes the purchase on their desktop at home. Different browser, different cookie jar, no attribution. Google estimates that cross-device conversions account for a significant portion of untracked Shopping activity.
The combined result: 10-30% of your Shopping conversions go unrecorded. Your ROAS looks worse than reality, your Smart Bidding algorithms optimize on incomplete data, and you undervalue products that actually perform well. Over time, this data gap compounds: you pull budget from "underperforming" products that were actually converting, feeding a cycle of bad decisions.
Enhanced Conversions Explained
Enhanced conversions solve the technical side of the data gap. When a conversion fires on your site, the tag collects customer data that the user provided at checkout (email address, phone number, name, or billing address), hashes it using SHA-256 on the client side, and sends the hashed values to Google alongside the standard conversion tag data.
Google then matches these hashed identifiers against its database of signed-in users. If the same person clicked your ad on their phone (signed into Chrome) and later purchased on their laptop (signed into Gmail), Google can connect the dots. The ad click and the conversion are linked, even though the cookies couldn't follow across devices.
The privacy model is straightforward: data is hashed before it leaves the browser. Google never sees the raw email address or phone number. They receive a one-way hash that can only be matched against other hashes, not reversed back to the original data.
Two types of enhanced conversions
- Enhanced conversions for web (e-commerce): The standard type for Shopping campaigns. Customer data is captured at the point of purchase and attached to the conversion tag. This recovers cross-device and cross-browser conversions for online sales.
- Enhanced conversions for leads: Designed for lead generation. Matches offline conversions (phone calls, in-store visits, closed deals) back to the original ad click using hashed customer data. Less common for Shopping but relevant if you drive leads through product ads.
Implementation options
- Google tag (gtag.js): Add enhanced conversion fields directly in your global site tag configuration
- Google Tag Manager: Configure enhanced conversions through GTM's built-in settings, mapping customer data fields to your checkout form
- Google Ads API: Send hashed conversion data server-side for maximum control and reliability
Typical recovery from enhanced conversions is 5-15% additional conversions attributed to your campaigns. The exact number depends on your audience profile: if most of your customers are signed into Google accounts and provide email at checkout, match rates are higher.
Consent Mode v2
Consent Mode v2 is Google's framework for handling user consent signals. It tells your Google tags (Analytics, Ads, Floodlight) how to behave based on what the user has agreed to. There are four consent signals: ad_storage, analytics_storage, ad_user_data, and ad_personalization. Each can be granted or denied independently.
The framework operates in two modes, and the difference matters significantly for your data.
Basic mode
Tags only fire when the user grants consent. If a user declines cookies, no Google tags load at all. You get zero data from that user. This is the minimum legal requirement, but it creates a large data gap because a meaningful percentage of EU users decline tracking.
Advanced mode
Tags load regardless of consent choice, but send cookieless pings when the user declines. These pings contain no personal identifiers and no cookies. Google uses them to build behavioral models that estimate what percentage of non-consenting users would have converted based on the patterns of consenting users. Google reports that Advanced mode can recover approximately 70% of otherwise lost conversions through this modeling.
EU Requirement Since March 2024
All advertisers serving users in the EU/EEA must implement Consent Mode v2. Without it, Google restricts remarketing audience building, limits the signals available to Smart Bidding, and may reduce your eligibility for certain ad formats. This applies regardless of where your business is located if your ads reach EU users.
Consent Mode works with any certified Consent Management Platform (CMP). Popular options include Cookiebot, OneTrust, and Usercentrics. The CMP presents the cookie banner, collects the user's choice, and passes the consent signals to your Google tags through the consent API.
How They Work Together
Enhanced conversions and Consent Mode solve different problems. Enhanced conversions handle the technical gap: cookies that expire, devices that don't share state, browsers that block trackers. Consent Mode handles the legal gap: users who decline tracking under GDPR or similar regulations. You need both for comprehensive coverage.
Here's how they complement each other across common scenarios:
| Scenario | Enhanced Conversions | Consent Mode |
|---|---|---|
| User consents + same device | Provides backup match if cookie expires | Full tracking active (consent granted) |
| User consents + different device | Critical — hashed data links cross-device journey | Full tracking active on both devices |
| User declines consent | Cannot fire (no consent for tracking) | Advanced mode sends cookieless pings for modeling |
| Ad blocker active | Cannot fire (tags blocked) | Cannot fire (tags blocked) |
The last row is important: neither technology helps when ad blockers prevent tags from loading entirely. That scenario is where server-side tagging fills the gap, since tracking requests go from your server to Google rather than from the user's browser.
Why you need both
Enhanced conversions alone miss users who decline consent. Consent Mode alone misses cross-device journeys from consenting users. Together, they cover the widest range of scenarios. The only gap they can't close is ad blockers, which require server-side tagging as an additional layer.
Implementation Guide
Implementing both enhanced conversions and Consent Mode v2 is a five-step process. The order matters: get consent mode working first so your tags respect user choices, then add enhanced conversions on top.
Step 1: Enable enhanced conversions in Google Ads
Go to Settings > Conversions in your Google Ads account. Select the purchase conversion action you want to enhance. Toggle on enhanced conversions and accept the terms. This tells Google Ads to expect hashed customer data alongside your standard conversion tags.
Step 2: Implement data capture
Configure your conversion tag to collect and hash customer data at checkout. If you use Google Tag Manager, open your conversion tag settings and enable enhanced conversions. Map the fields (email, phone number, first name, last name, street address, city, region, postal code, country) to the corresponding variables on your checkout confirmation page. Email is the most important field and typically produces the highest match rates.
If you use gtag.js directly, add the user_data object to your conversion event with the appropriate fields. Google's tag automatically handles the SHA-256 hashing before sending.
Step 3: Configure your CMP for Consent Mode v2
Set up your Consent Management Platform to pass the four consent signals to Google tags: ad_storage, analytics_storage, ad_user_data, and ad_personalization. Most major CMPs (Cookiebot, OneTrust, Usercentrics) have built-in integrations for Consent Mode v2. Follow your CMP's documentation to map their consent categories to Google's consent types.
Step 4: Choose Advanced mode
Configure your Google tags to load in Advanced mode rather than Basic. In Advanced mode, tags load on page view but only set cookies and collect identifiers when consent is granted. When consent is denied, they send cookieless pings that enable Google's behavioral modeling. This is the critical difference: Advanced mode recovers data from non-consenting users, Basic mode does not.
Step 5: Validate
Check three things after implementation:
- Enhanced conversion diagnostics: In Google Ads, go to Settings > Conversions and click the Diagnostics tab. Verify that enhanced conversions are active and check the match rate (target: 60-80%).
- Consent mode status: Use Google Tag Assistant or the browser console to verify that consent signals are being sent correctly. Test both the "accept" and "decline" flows.
- Conversion counts: After 1-2 weeks, compare conversion totals to your pre-implementation baseline. You should see an increase from the enhanced conversion matches.
The full process typically takes 1-2 weeks for implementation and another 2-4 weeks to measure impact accurately, accounting for conversion lag.
Measuring Impact
Once both technologies are live, measure their combined effect using a before/after comparison and segmented analysis.
Before/after comparison
Compare total attributed conversions for the 4 weeks before implementation against 4 weeks after. Account for seasonality and any other changes you made during that period. A clean test means changing nothing else during the measurement window. Expect to see 5-15% more conversions attributed to your Shopping campaigns overall.
Segment by country
EU countries should show the biggest improvement from Consent Mode. If a large portion of your traffic comes from Germany, France, or other EU markets where cookie consent rates are lower, the behavioral modeling from Advanced mode will have the most room to recover data. Non-EU markets will primarily benefit from enhanced conversions (cross-device and cookie expiry recovery).
Segment by device
Cross-device conversions should increase after enabling enhanced conversions. Look specifically at the mobile click-to-desktop purchase path. If your analytics show a higher share of conversions attributed to mobile clicks, enhanced conversions are doing their job of connecting the cross-device journey.
Check diagnostics
Google Ads provides two key diagnostic metrics:
- Enhanced conversion match rate: The percentage of conversions where Google successfully matched the hashed customer data to a signed-in user. Target 60-80%.
- Modeled conversion percentage: The share of your total conversions that come from Consent Mode's behavioral modeling rather than direct observation. This shows how much data you'd be missing without Advanced mode.
What it means for your dashboard
More conversions attributed means more accurate ROAS calculations at the product level. Products that previously looked like zero-conversion drains may turn out to have been converting all along, just through untracked paths. This improves the decisions you make in tools like SKU Analyzer, where product-level data drives budget allocation. The ROAS you see in your dashboard gets closer to reality, which means better input for bidding strategies and budget planning.
Frequently Asked Questions
Is enhanced conversions GDPR compliant?
Yes, the customer data is hashed using SHA-256 before it leaves the browser, so Google never sees the raw email or phone number. However, you still need proper consent for the base conversion tag itself. Enhanced conversions handle the technical matching; Consent Mode handles the legal consent layer. Both together ensure compliance and accuracy.
Do I need a CMP for Consent Mode?
Yes, you need a Consent Management Platform to collect user consent and pass the signals to Google tags. Popular options include Cookiebot, OneTrust, and Usercentrics. The CMP presents the cookie banner, records the user's choice, and communicates it to your Google tags through the consent API.
What match rate should I expect?
Typical enhanced conversion match rates are 60-80%, depending on how many customers provide email addresses at checkout. Guest checkout with email collection tends to produce higher match rates. You can check your match rate in Google Ads under Settings > Conversions > Diagnostics.
Does this replace server-side tagging?
No, they are complementary. Enhanced conversions and Consent Mode run client-side and improve attribution for users who reach your site. Server-side tagging adds another recovery layer by bypassing ad blockers entirely, since the tracking request goes from your server to Google rather than from the user's browser. For maximum conversion recovery, implement all three.