Google Ads conversions dropped after Consent Mode?

The short answer

First check that real orders or leads held steady. If they did, the drop is measurement. After a banner or Consent Mode change, the usual cause is one of three: the banner sends only the old two consent signals, so even an Accept goes cookieless; the consent defaults arrive after the tag; or Google's tag is held completely until consent. The table below matches each to what you'll see, and one conversion hit in DevTools tells you which you have.

Consent Mode is how your cookie banner tells Google's tags what a visitor agreed to. If the term is new, start with Consent Mode v2, explained.

Tracking or demand?

Compare Google Ads with something a banner can't touch: orders in your shop, leads in your CRM, booked calls. If those held steady while Ads conversions fell, the problem is measurement and this page is for you.

If they fell too, it's demand or the campaigns. Smart Bidding learns from conversions, so a measurement drop can turn into a real one: fewer recorded conversions, lower bids, fewer impressions. That's why it's worth fixing quickly.

Also check the dates. Google reports conversions against the day of the click, not the day of the sale, and its reports can lag 24 to 48 hours, so the last two days can look low.

What a conversion hit carries: our test

We built a thank-you page that loads Google's real tag for a made-up Ads account and fires one conversion worth $42. Then we ran it under six consent setups and recorded every request the tag made to Google, stopping each one before it left the browser.

Setup	Where the conversion went	Consent state (`gcs`)	Ad click cookie (`_gcl_au`)	Remarketing
No consent code at all	googleadservices.com	none	set	yes
Denied by default, visitor hasn't answered	pagead2.googlesyndication.com, cookieless	G100	none	no
Denied by default, then Accept all	googleadservices.com	G111	set	yes
Denied by default, then an Accept that grants only the two old signals	pagead2.googlesyndication.com, cookieless	G111	none	no
Default set after the tag ran	googleadservices.com with no consent state (cookie set before the denial landed), then google.com/pagead/1p-conversion	none, then G100	set	yes
Google's tag held until consent, no answer	nothing sent

Look at the fourth row. That visitor clicked Accept, and gcs reads G111 (ad_storage and analytics_storage granted), yet the hit took the same cookieless route as a refusal and no cookie was set.

Google's consent reference explains it: when ad_user_data is denied, "multiple cookies are limited, causing conversion pings to be sent as cookieless pings." A banner built before Consent Mode v2 never sends ad_user_data, and Google treats a signal that isn't set as not granted.

We ran this on 16 October 2026 in Chromium, with Google's tag as served that day. Google changes its tag often, so the hosts may move, but the pattern is what to look for.

The triage table

What you see	Likely cause	The fix
Drop starts the day a banner went live, mostly from places where it asks first	Fewer people agree, and Google needs time to model the rest	Expected. Check modelling eligibility (below)
Conversions fell even for people who clicked Accept	The banner sends only `ad_storage` and `analytics_storage`	Update the banner to send all four v2 signals, including `ad_user_data` and `ad_personalization`
Remarketing lists stopped growing	`ad_personalization` is denied or never sent	Same fix: send `ad_personalization` on Accept
"Consent mode installation out of order" in Tag Diagnostics	Defaults load after the Google tag	Set the consent default above Tag Manager and every Google tag
No Google requests at all before a choice	Google's tag is held until consent (basic mode)	Pick on purpose: basic sends nothing to model, advanced sends cookieless pings
GA4-imported conversions can fall further than the Ads tag's	Without `ad_user_data`, Google limits the click-keyed conversion data it exports to Ads	Check Admin › Consent settings in GA4
Status reads "Misconfigured"	Conversions stopped recording, usually a broken tag	Not consent. Check the tag fires on the thank-you page
Status reads "Awaiting conversions"	Nothing recorded in 7 days	A new action, paused campaigns or low traffic

For the alerts themselves, our guide to consent mode not detected in Google Ads decodes each one. If GA4 dropped as well, the four causes of an analytics drop cover that side.

Check one hit in two minutes

Open your thank-you page in a private window, open DevTools, go to the Network tab and filter for conversion. Then make a test purchase or form submission.

Before you answer the banner, look for a request to pagead2.googlesyndication.com. If you see one, the defaults work and the tag runs cookieless. If there's no request at all, the tag is held.
Click Accept and convert again. The hit should go to googleadservices.com (or google.com/pagead/1p-conversion) and the _gcl_au cookie should appear under Application › Cookies.
If an Accept still goes to googlesyndication.com and its gcs reads G111, your banner isn't sending ad_user_data. That's the fourth row of our test.

Our Consent Mode v2 checklist has the longer version, with Tag Assistant.

What Google fills back in

In advanced mode (cookieless pings before a choice), Google models the conversions of people who refused. It needs 700 ad clicks over 7 days, per country and domain grouping. Modelled conversions then appear gradually in the normal Conversions column.

Basic mode sends nothing before consent, so Google can only use a general model, not one trained on your site. Google also says consented users are typically 2 to 5 times more likely to convert than those who refuse, so expect the gap to stay partly open.

While you wait, read the status on each conversion action. The Conversions summary shows five: Active, Needs attention, Misconfigured, Awaiting conversions and Removed. Google says some status details are still rolling out, so a few may not show in your account yet.

Where TagSentry fits

TagSentry is one line of code above Google Tag Manager. It sets every Consent Mode signal to denied before any tag runs, ad_user_data included, and each visitor gets the right consent for their country. Google's tags run cookieless until a visitor agrees, so Ads can still model the conversions it can't see.

Event monitoring watches every destination your tags send to, with Google Ads as its own. It emails you once when an event that matters stops arriving, like a purchase, and once when it recovers.