# Why conversions vanish after a cookie banner

> Why GA4 and ad platforms lose conversions once a consent banner goes live, and how MIRA FIVE counts visits without cookies and people only with consent.

URL: https://mirafive.io/learn/conversions-missing-after-cookie-banner  
Updated: 2026-09-28

Short answer

Tools that set cookies measure only the visitors who accept, and with a compliant banner many decline. MIRA FIVE counts visits, channels and campaigns without cookies in its default setup and follows people only with consent. On a website source set to Full, each page picks the mode per visitor, and the dashboard shows how much of your traffic was collected with consent.

You put up a compliant consent banner, and the next month GA4 and Google Ads reported fewer conversions while your shop sold as much as before. The orders are still there. The tools lost sight of the visitors who declined, and MIRA FIVE can count those visits another way.

## Why do conversions go missing after a cookie banner?

Because tools that set cookies or store an identifier have to wait for a yes. A visitor who declines is measured partly or not at all, and so is the purchase they make later. In etracker’s [2025 consent benchmark](https://www.etracker.com/en/cookie-consent-benchmarks/), consent-requiring cookies and data processing were rejected in 60% of visits when the banner was designed in a legally compliant way.

The rate also differs by industry, referral source and medium, according to the same study. So the gap is uneven across channels: a channel whose visitors decline more often looks weaker than it is.

## Does modeling fill the gap?

For large sites, partly. GA4’s [behavioral modeling for consent mode](https://support.google.com/analytics/answer/11161109) estimates what visitors who declined did, once a property has at least 1,000 events a day from them for at least 7 days, and at least 1,000 daily users who consented on at least 7 of the previous 28 days. A shop with a few hundred visitors a day stays below that line, and above it the result is an estimate.

## What does MIRA FIVE count without consent?

Visits, pages, channels, campaigns, countries, devices and events. The default setup sets no cookies, stores nothing on the device, sends no identifier and does not read the browser’s language, time zone or screen size. What it gives up is recognition: one visit is not linked to the next.

Traffic questions keep their answer: how many visits each channel and campaign sent, where they landed, and how many conversions happened per visit. Visitors whose browser sends Do Not Track or Global Privacy Control are not counted. A project that collects only without consent shows Visits, Pageviews, Conversions and Conversions per visit on its Overview.

## What needs consent?

Everything that follows a person: People, the journey map, funnels, first touch across visits and buyers per channel. Full mode serves those visitors. Nothing is sent or stored until they answer, your banner passes the answer with `mirafive('consent', …)`, and ids live in localStorage, never in cookies.

Switch the website source to **Full** under **Data → Sources**. It then accepts both kinds of data, and each page picks the mode for its visitor: the default setup while there is no yes, full mode once your banner has one. A `data-mode="full"` tag alone sends nothing for visitors who decline. The [consent guide](https://docs.mirafive.io/guides/consent) shows the setup. The dashboard then shows the share collected with consent, for example “85% with consent”. Visits and campaigns count both kinds of traffic; people, buyers and journeys rest on the consented share.

## How do I keep purchases complete?

Send them from your server. A paid order your backend sends arrives whatever happens in the browser, so Goals count it with its revenue:

```ts
mira.track('order_paid', {
  userId: order.customerId,
  properties: { revenue: 328, currency: 'EUR' },
})
```

With the customer’s user id, the order joins their person and the channel that brought them, where their browser was followed with consent. Which ids you send, and on what basis, is your decision. The guide to [setting up a purchase goal](https://mirafive.io/learn/from-first-visit-to-paid-plan) walks through it.

## Where does compliance come in?

MIRA FIVE is run by Cloo GmbH in Auerbach, Germany, and hosted in Germany; analytics data is received and stored in Germany. Hosting and the default setup are one part of compliance. Whether your setup is compliant depends on what you collect and why, across your whole site, so the decision about your banner stays with you. The [Trust](https://mirafive.io/security) page lists what MIRA FIVE does with data.

## How to do it in MIRA FIVE

1. Add the MIRA FIVE script. The default setup counts visits, channels and campaigns from the first day, without cookies.
2. Create a goal for your purchase or sign-up under **Goals**. Without consent, it counts conversions per visit.
3. For people and journeys, switch the website source to **Full** under **Data → Sources**. Load full mode for visitors who agreed and the default setup for everyone else, and pass your banner’s answer with `mirafive('consent', …)`.
4. Send paid orders from your server with their revenue.
5. Read the share with consent on the dashboard, and compare visits per channel with buyers per channel.

## What this leaves out

- Buyers per channel rest on visitors who consented. When one channel’s visitors decline more often, read its buyers beside its visits.
- The benchmark and Google’s thresholds describe other sites and other tools. Your own consent coverage is the number to watch.

## Questions and answers

### Does MIRA FIVE mean I can remove my cookie banner?

That depends on everything your site collects and why, not on analytics alone. The default setup sets no cookies and stores nothing on the device; the rest of the assessment stays with you.

### How many visitors decline a cookie banner?

With a legally compliant design, etracker's 2025 benchmark found consent-requiring cookies rejected in 60% of visits. Your own share depends on audience and banner, and MIRA FIVE shows it as consent coverage.

### Does GA4 model the conversions it misses?

Only above a threshold. Google requires at least 1,000 events a day from visitors who declined, for 7 days, and 1,000 daily users who consented on 7 of the previous 28 days.

### Are purchases sent from my server counted?

Yes. A server event arrives whatever happens in the browser. It joins a person and their channel when that visitor's browser was followed with consent.

## Read next

### [Which channel brings the customers who pay?](https://mirafive.io/learn/which-channel-brings-paying-customers)

Rank marketing channels by the buyers they bring instead of visits, with first or last touch, revenue per channel, campaigns and Google Ads cost per buyer.

### [How to set up a purchase goal](https://mirafive.io/learn/from-first-visit-to-paid-plan)

Set up conversion tracking with a purchase goal, revenue read from your events, one total per currency, and the time from first visit to paid plan.

### Related terms

- [Consentless analytics](https://mirafive.io/glossary/consentless)
- [With consent](https://mirafive.io/glossary/with-consent)
- [First-party collection](https://mirafive.io/glossary/first-party)

[All guides](https://mirafive.io/learn)

## See which channel brings buyers

Free for 25,000 events a month. No card needed.

[Start free](https://app.mirafive.io/register)[See pricing](https://mirafive.io/pricing)