The essentials
- Definition: a CMP (Consent Management Platform) is the tool that displays the cookie banner, records the visitor's choice and passes it on to the site's tags.
- Obligations: refusing must be as easy as accepting, no non-essential cookie before the choice is made, proof of consent kept, and withdrawal possible at any time.
- 2026 benchmarks: a consent rate of 55 to 75% on a compliant, well-designed banner, against 30 to 45% on a badly worded one.
- Costs: free for small sites with several vendors, €10 to €100 a month for a small business, more beyond a million page views.
A CMP (Consent Management Platform) is the tool that manages cookie consent on a site: it displays the banner, records the visitor's choice, keeps it as proof and passes it to your measurement and advertising tags. It has become a mandatory component of any site using non-essential cookies, and the technical precondition for Google's Consent Mode .
What a CMP does
- Display the information: the purposes of the cookies, the recipients, the retention period, in language people can understand.
- Collect the choice: accept all, refuse all, or a choice by purpose (measurement, advertising, personalisation, social media).
- Block before the choice: no non-essential cookie and no third-party script may fire until the visitor has answered.
- Pass on the signals: to Google's tags (the four Consent Mode v2 signals), to Meta, to third-party tools, generally through Google Tag Manager.
- Keep the proof: a timestamped record of the choice, required in the event of an inspection.
- Allow withdrawal: a permanent link to change the choice, usually in the footer.
The French rules to follow
France's data protection authority has set out several requirements whose breach has already led to penalties of tens of millions of euros against major players. Refusing must take the same number of clicks as accepting, which rules out the single-button "I accept" banner. Simply carrying on browsing does not count as consent. Strictly necessary and anonymised audience measurement cookies can be exempt, but GA4 in its standard configuration is not. Consent may be asked again at most every six months after a refusal, and the recommended retention period for it is six to thirteen months. The full framework is set out in GA4 and the GDPR.
Choosing a CMP
| Criterion | What to check |
|---|---|
| Google certification | A certified CMP partner, a condition for Consent Mode v2 and for continuing to advertise on Google Ads in the EEA |
| Automatic blocking | The ability to stop third-party scripts firing before the choice, with no development work |
| Tag Manager integration | A ready-made template for passing the signals to your tags |
| Customisation | Text, colours and layout adaptable to your brand, which weighs on your consent rate |
| Multilingual and multi-domain | Necessary as soon as a site has a foreign version or several domains |
| Proof log | Export of timestamped consents |
| Data hosting | In the European Union for preference, to keep compliance simple |
The main solutions on the market are Axeptio, Cookiebot, Didomi, Osano, Usercentrics and the free modules built into some CMSs. The 2026 cost runs from free for small sites to €10 or €100 a month for a small business, depending on page view volume and logging features.
The consent rate, a measurement issue
Every refusal removes a visitor from your statistics and your advertising audiences. On a compliant, carefully made banner, the acceptance rate sits between 55 and 75% in France in 2026; on a badly designed one it falls to 30 or 45%. Three levers make the difference: short text explaining the concrete benefit ("to measure our audience and improve the site") rather than a wall of legal language, a design that matches your brand rather than a generic banner, and a display that doesn't block people from reading the page. Any attempt to steer the choice through deceptive devices (a greyed-out refuse button, tiny text) risks a penalty and durably damages your relationship with visitors.
How GreenRed helps
Rather than juggling several tools, GreenRed's Site health module brings these metrics together in a single dashboard, compares them over time and tells you which actions come first. You can try it free, with no card, from the Pricing.
Frequently asked questions
What is a CMP?
A consent management platform: the tool that displays the cookie banner, collects the visitor's choice, stops non-essential scripts firing before that choice, passes the signals to your tags and keeps proof of consent.
Is a CMP mandatory?
As soon as a site sets non-essential cookies (non-anonymised audience measurement, advertising, social media), a compliant consent mechanism is mandatory. The CMP is the standard way of implementing it; it is also the technical precondition for Google's Consent Mode v2.
What consent rate should you aim for?
Between 55 and 75% in France on a compliant, well-designed banner. Below 50%, the problem usually lies in the text (too legalistic), the design (a generic banner) or a display that blocks reading. Deceptive devices are penalised and should be ruled out.
What does a CMP cost in 2026?
Several vendors offer a free tier for low-traffic sites, as do some CMS modules. A small business pays between €10 and €100 a month depending on page view volume, multilingual support and consent logging features.