Google Consent Mode v2: What It Changes for Ads and Analytics

Consent Mode v2 is the mechanism that lets your website tell Google’s tags what each visitor has agreed to, and lets those tags behave accordingly. For years, a cookie banner and the marketing tags behind it were separate things: the banner collected a choice, and somebody was supposed to make sure the tags respected it. Consent Mode connects the two. When a visitor declines advertising cookies, the Google tag on the page is told so and adjusts what it stores and sends. When a visitor accepts, everything works as normal. The “v2” refers to two extra signals added in 2024, which Google requires for personalised advertising features with visitors in the European Economic Area.

This guide explains the four signals, the difference between basic and advanced implementations, what happens to your measurement when people say no, how to set it up with a consent banner and tag manager, and how to test that it works. It is written for business owners, marketers and developers who run Google Ads or Google Analytics on a website with European visitors. It is not legal advice, so check your obligations with a qualified adviser.

Why It Matters

There are two reasons to care. The first is legal and ethical: privacy rules in Europe, especially the ePrivacy rules and the GDPR, require valid consent before non-essential cookies and similar technologies are placed or read. The European Data Protection Board publishes guidance and opinions on how consent should be collected. The second is commercial: Google asks advertisers to send consent signals for visitors in the EEA and the United Kingdom, and its EU user consent policy makes that part of the terms of using its advertising products. Without proper signals, features such as remarketing audiences and conversion measurement for those visitors can stop working or be limited.

So a well-implemented consent setup protects your visitors, reduces your legal risk and keeps your advertising measurable. For the broader legal picture, our article on cookie consent, GDPR and website privacy compliance is the place to start.

The Four Consent Signals

Consent Mode v2 uses four parameters. Each one is set to granted or denied, based on the visitor’s choice.

• ad_storage controls whether advertising-related cookies and identifiers can be stored, such as those used for remarketing.
• analytics_storage controls whether analytics cookies can be stored, such as those Google Analytics uses to recognise a visit.
• ad_user_data controls whether user data may be sent to Google for advertising purposes. This is one of the two signals added in v2.
• ad_personalization controls whether data may be used for personalised advertising, such as remarketing. This is the other added in v2.

The technical detail is described in Google’s developer guide to managing consent for tags. In practice, you do not set these values by hand. A consent management platform, usually shortened to CMP, sets them from the choices made in your banner.

Basic Mode and Advanced Mode

There are two ways to implement it, and they differ in what happens before a visitor chooses.

Basic mode

Google tags are blocked entirely until the visitor gives consent. If the visitor declines, no data goes to Google from that visit. This is the most conservative option and the simplest to explain to a privacy officer. The cost is that you have no measurement at all for visitors who decline, and Google’s conversion modelling has less to work with.

Advanced mode

Tags load on every page, but with consent defaulted to denied. Until consent is given, the tags send limited, cookieless signals, and when consent is granted they switch to normal behaviour. Google can use the cookieless signals to model conversions for visitors who did not consent, which fills part of the gap. Whether this approach is acceptable for your organisation depends on your legal assessment and your jurisdiction, so decide it with advice instead of choosing it just for the numbers.

What Changes in Your Reports

After you introduce Consent Mode, expect a visible effect. Some visitors decline, so your tracked users, sessions and conversions fall compared with a period when tags fired regardless. That drop reflects reality: those visitors never agreed to be measured. Google may fill part of the gap with modelled data, where it estimates conversions for non-consenting users from patterns among consenting ones. Modelling has conditions, such as minimum data volumes, and it does not restore individual-level detail. Reports will mix observed and modelled values, so mark the change date in your reporting and avoid comparing numbers across it without explanation.

The impact on audiences is also direct. Remarketing lists are built from visitors who allowed advertising storage and personalisation, so lists shrink when consent is lower. Our article on Google Ads remarketing describes how lists are used, and it is worth reviewing list sizes after the change.

Setting It Up Step by Step

1. Choose a consent management platform that supports Consent Mode v2. Google maintains a list of certified partners for EEA advertising, and many CMPs integrate with tag managers directly.
2. Configure the banner honestly. Offer “accept” and “reject” with equal prominence, explain purposes clearly and make withdrawing consent as easy as giving it.
3. Set default consent states to denied for the regions where you need consent, before any Google tag fires. The order matters: defaults must be set before tags load.
4. Update consent on choice. The CMP sends an update when the visitor accepts or declines, changing the four signals.
5. Configure your tags in Google Tag Manager or on the site, and use the consent settings of each tag so that it fires only when appropriate.
6. Add the Google tag or GA4 configuration with consent checks, and check that conversion tags for Google Ads include the proper consent requirements.
7. Publish and test in preview mode and in a normal browser session.

The Google Tag Manager documentation on consent configuration explains the built-in consent checks for tags. Conversion tracking depends on this setup, so our guide to conversion tracking that holds up is a useful companion.

How to Test That It Works

• Open the site in a private window and look at the network requests and cookies before you click anything on the banner. With defaults set to denied, no advertising or analytics cookies should appear.
• Click “reject” and check that the signals remain denied and cookies stay absent.
• Click “accept” and verify that the signals change to granted and tags behave normally.
• Use tag preview tools to view the consent state for each tag, and check that each consent update appears in the event stream.
• Check key pages and forms, such as checkout and thank-you pages, where conversion tags fire.
• Retest after every site or banner update, since changes to templates or scripts can break the sequence.

Google Analytics also reports whether consent signals are being received, as described in the help pages on Consent Mode. Keep a short test record with the date, the browser and the results.

A Worked Example of the Sequence

It helps to follow one visit from start to finish. A visitor from Germany opens your product page. Before anything else happens, your site sets the default consent state: all four signals denied. The Google tag loads, sees the denied state and, in advanced mode, sends only a minimal, cookieless signal about the page view. The banner appears. The visitor chooses “accept advertising and analytics”. The banner software sends an update that changes all four signals to granted, and the tags now behave normally, storing cookies and sending the full event data. Later in the session the visitor buys a product, and the conversion is recorded and attributed as usual.

Now take a second visitor who declines. The signals stay denied for the whole session. No advertising or analytics cookies are stored, no remarketing audience is built from the visit, and the purchase, if it happens, may appear only as a modelled conversion in aggregate. If that visitor returns next week, the banner should remember the earlier choice, so you do not ask again on every page. The point of the example is the order of events: default first, choice second, behaviour following the choice. Most failures come from getting that order wrong, usually because a hard-coded tag in the page template loads before the banner software has set the defaults.

Regions and Defaults

Consent rules differ by region, and a single global default may be too strict in some places and too loose in others. Many consent platforms let you set defaults by country, so that visitors in the EEA, the United Kingdom and Switzerland start with everything denied, while visitors in places with different rules start with a different state. Keep this configuration simple, document it and review it when laws or your audience change. If you serve a worldwide audience and are unsure which rules apply, applying the strictest standard everywhere is the lowest-risk option, at the cost of some measurement. Whatever you choose, make sure the privacy notice describes it accurately and that visitors can change their choice at any time through a visible link, such as “Cookie settings” in the footer.

Alternatives and Complements

Consent Mode is not the only part of a privacy-conscious measurement setup. Server-side tagging, first-party data collection with permission and privacy-friendly analytics tools can complement it. If a large share of your visitors decline, consider whether a cookieless analytics approach would give you the figures you need without the same constraints. Our article on privacy-friendly website analytics describes the options, and our online advertising specialists can help match the setup to your campaigns.

Common Mistakes

• Setting default consent after tags have already loaded.
• Showing a banner with a prominent accept button and a hidden reject option.
• Using a CMP that does not send the two v2 signals.
• Forgetting the countries outside the EEA that have their own rules, such as the United Kingdom and Switzerland.
• Comparing reports before and after implementation without a note.
• Assuming that modelling replaces missing data completely.
• Leaving old hard-coded tags in templates that ignore consent.

Frequently Asked Questions

Is Consent Mode a cookie banner?

No. A banner collects the visitor’s choice. Consent Mode passes that choice to Google tags and adjusts their behaviour. You need both.

Is Consent Mode v2 mandatory?

Google requires consent signals for advertisers who use its personalised advertising features with visitors in the EEA and the United Kingdom. Without them, features such as remarketing and some conversion measurement may stop working for those visitors.

What is the difference between ad_storage and ad_user_data?

ad_storage covers cookies and identifiers stored on the device for advertising. ad_user_data covers sending user data to Google for advertising purposes, so each controls a different part of the process.

Will my numbers drop?

Probably, because visitors who decline are no longer measured individually. Google may add modelled conversions, but expect a visible change and annotate your reports.

Do I need a certified CMP?

For serving personalised ads in the EEA, Google expects a consent solution that meets its requirements, and using a certified partner simplifies compliance. Check the current requirements before choosing.

Does this make me GDPR compliant?

Not on its own. It is a technical tool. Compliance depends on valid consent, a clear privacy notice, a lawful basis, data processing agreements and more. Ask a qualified adviser.

The Bottom Line

Consent Mode v2 links your banner to Google’s tags so that advertising and analytics respect each visitor’s choice. Choose a capable consent platform, set defaults before any tag fires, decide between basic and advanced mode with legal advice, test in a clean browser and document the change in your reports. You will lose some visibility, but you will keep your campaigns working within the rules and show visitors the respect they expect. For help planning your tracking and advertising setup, see our online advertising page.