How Consent Mode Affects Your Google Ads Conversion Data (Modeled Conversions Explained)

The Data Gap Consent Mode Addresses

When a user declines cookie consent, standard JavaScript-based Google Ads conversion tracking cannot fire. The Google Ads tag relies on cookies to connect an ad click to a later conversion — without cookies, that attribution chain breaks.

For businesses in the EU and EEA where consent rates are often 40-70%, this means a significant proportion of conversions simply disappear from your data. Smart Bidding, which relies on this conversion data, has an incomplete picture — and bids suboptimally as a result.

Consent Mode v2 is Google's solution to this problem.

How Consent Mode Works

When a user declines cookies and Consent Mode is implemented, the Google tag does not fire its standard tracking code. Instead, it sends a minimal "ping" to Google — no personal identifiers, no conversion data — that simply signals a visit occurred from someone who declined consent.

Google then uses these pings, combined with aggregated patterns from consenting users, to model the conversions that likely occurred from non-consenting users. This is called conversion modeling or behavioral modeling.

What Modeled Conversions Are

Modeled conversions are Google's statistical estimate of the conversions that happened from users who did not consent to cookies. They are added to your observed (directly tracked) conversion data to give you a more complete picture.

For example: if 60% of your users consent to cookies and your observed data shows 100 conversions from consenting users, Google might model an additional 40-60 conversions from the non-consenting 40% based on behavioral patterns. Your total reported conversions would be 140-160, of which 100 are observed and 40-60 are modeled.

The Two Consent Mode Versions

• Basic Consent Mode: the Google tag does not load at all for non-consenting users. No ping is sent. No modeling can occur. Your conversion data simply has a gap for all non-consenting users.
• Advanced Consent Mode: the Google tag loads but with all cookies and personal data restricted for non-consenting users. A consent-less ping is sent to Google. This enables behavioral modeling to partially fill the gap.

Advanced Consent Mode is strongly recommended — it significantly improves the completeness of your conversion data versus Basic.

Where Modeled Conversions Appear

In Google Ads reports, modeled conversions are included in the standard "Conversions" column alongside observed conversions. Google does not always show a separate column for modeled vs observed — the combined number is what Smart Bidding sees and uses.

In GA4, you can see the split between observed and modeled data in some reports and via BigQuery export.

How This Affects Smart Bidding

The goal of Consent Mode is to give Smart Bidding a more accurate picture of total conversions, including those from non-consenting users. Without modeling, Smart Bidding sees an artificially low conversion count and may underbid for audiences that are actually converting at high rates.

With Advanced Consent Mode and modeling:

• Smart Bidding has a more complete conversion signal
• CPA targets reflect total conversions including modeled ones
• Budget allocation improves as the algorithm has better data

Note: modeled conversions are statistical estimates, not certainties. The accuracy depends on the volume of consenting users providing the baseline pattern. Low consent rates (under 30%) limit modeling accuracy.

Improving Your Consent Rate

The best data comes from actual consent — not modeling. Alongside implementing Consent Mode, invest in improving your consent banner's opt-in rate. Placing the banner in a clear but non-intrusive position, using neutral language, and not making the reject button smaller than the accept button all improve consent rates without sacrificing compliance.

See our Consent Mode v2 Implementation service for a complete setup.

Summary

Consent Mode v2 with Advanced implementation allows Google to model conversions from non-consenting users, reducing the data gap caused by cookie rejection. It does not fully replace consented tracking but significantly improves the completeness of conversion data for Smart Bidding.

If you are operating in the EU without Consent Mode, you are likely seeing materially incomplete conversion data in your Google Ads account.

Need help implementing Consent Mode v2? Contact Adslytics.