Consent Mode v2: how to check it on your shop

Why it matters

Since March 2024, Google requires sites to send Consent Mode v2 signals for visitors from the European Economic Area. Without them, Google Ads limits remarketing audiences, personalised ads and part of conversion measurement. In Google Ads this usually shows as a warning on conversion actions or in tag diagnostics.

The second reason is the law. A shop may store analytics and advertising cookies only with consent. Consent Mode does not collect consent; the cookie banner does. Consent Mode makes sure Google’s tools actually follow the choice made on the banner.

Four signals, two states

Consent Mode v2 uses four signals. Each is either granted or denied:

• ad_storage: storing cookies for advertising, such as Google Ads.
• analytics_storage: storing cookies for analytics, such as GA4.
• ad_user_data: sending user data to Google for advertising. New in version 2.
• ad_personalization: using data for personalised ads and remarketing. New in version 2.

Two things must happen in order. First the default state, with all four signals “denied” for visitors from the EEA. It must be set before any Google tag loads. Then the update, when the visitor clicks the banner. On later visits the update is sent at page load from the stored choice.

How the main platforms handle it

• Shopify: the built-in banner and apps that use the Customer Privacy API pass consent to Google’s sales channel. Code pasted into theme.liquid ignores it. See cookie banner on Shopify.
• WooCommerce: the consent plugin (Complianz, CookieYes, Cookiebot and others) sets Consent Mode, but only for tags it knows about. A second copy of GA4 from another plugin often runs outside it. See cookie banner on WooCommerce.
• PrestaShop: consent modules differ in how they set the default state. Tags added by other modules or in the theme need to be connected by hand. See cookie banner on PrestaShop.
• Any platform with Google Tag Manager: the default must be set on the Consent Initialization trigger, and every non-Google tag needs its own consent condition.

Step-by-step check

You need Chrome and a Google account. No access to your shop admin.

1. Open Tag Assistant

   Go to tagassistant.google.com, click Add domain, enter your shop address and click Connect. A new window opens with your shop, and events start to appear in the original tab.

2. Do not click the banner yet

   Leave the banner alone in the shop window. In Tag Assistant pick your tag (G-… or GTM-…) and the first event in the left column, usually Consent or Initialization.

3. Check the default state

   Open the Consent tab. In the On-page Default column all four signals must be “Denied”. If the default is empty, or appears only on an event after the first tag fired, Consent Mode is set up wrong.

4. See which tags fired

   In the Tags tab of the first event, check whether Google Ads or Meta tags already fired. In advanced mode Google tags may fire, without cookies. Tags from other vendors (Meta, TikTok, Microsoft Ads) must not fire.

5. Accept

   In the shop window accept all cookies. A new event appears in Tag Assistant, and the On-page Update column must show “Granted”. If there is no update, the banner does not pass the choice to Google.

6. Repeat with reject

   Disconnect Tag Assistant, open a private window and repeat with the reject button. The update must stay “Denied”, and Meta and TikTok tags must not fire, also after moving to the next page.

7. Extra: the gcs parameter

   In the developer tools (F12, Network tab) search for collect. On GA4 requests look for the gcs parameter: G100 means denied, G111 granted. A request without gcs was sent without Consent Mode.

The mistakes we find most often

• The default set in GTM by a tag on the “All Pages” trigger. That is too late; it belongs on Consent Initialization.
• A default of “granted”, copied from a template found online.
• Meta Pixel or TikTok in GTM with no consent condition. Consent Mode covers Google only; other tags must wait for consent on their own.
• A Google Ads conversion snippet pasted into the order confirmation page next to the platform integration. Conversions then count twice, and one copy ignores consent.
• GA4 installed by the platform and again in GTM. Visits count twice and one path ignores the banner.

If the check fails

First remove hard-coded Google tags from the theme and from extra apps or plugins, then repeat the check. Most broken setups pass once each tool loads by one path only.

If you use GTM, the default has to go on the Consent Initialization trigger, the update has to be tied to your banner, and every tag needs consent settings. We do this as fixed-price work: €59 excl. VAT, paid only after we verify the result with the same steps as in this guide.