Cookieless tracking with Matomo: How to stop losing leads

TL;DR

GA4 only tracks with consent. Visitors who decline or ignore the cookie banner are invisible in your reports.
ganztags. runs Matomo in cookieless pre-consent mode. That gives us reliable data, we see every conversion and where it actually came from.
Matomo in cookieless mode doesn't do cross-device attribution or automatic data exchange with Google Ads Smart Bidding.
Cookieless tracking with Matomo makes sense for B2B sites with lead generation, less so for e-commerce shops with a large ad budget.

When it comes to tracking, we decide pragmatically for each client what actually fits their business model: GA4, Consent Mode v2, server-side tracking, sometimes a combination of all three.

At ganztags., we run Matomo, self-hosted, with cookieless pre-consent. Not for privacy reasons, but because we want to know where every lead actually comes from.

The conversion problem nobody likes to talk about

If you're running a standard GA4 setup, you know the pattern: 100 visitors land on the page. 50 click "Decline" on the consent banner or ignore it altogether. That makes those 50 people invisible to GA4, including the contact forms they submit and the demo bookings they trigger.

At the end of the month, your backend shows 20 leads. How many there actually were, nobody knows.

That becomes a real problem once you have to answer questions like these:

"Which channel brings the best leads?" If half your leads are missing from the tool, source attribution goes with them. You're optimizing budget based on half your data.
"Did the SEO push for that keyword cluster pay off?" Organic visitors decline the banner more often than average (this happens a lot), so the channel gets systematically undervalued.
"Which landing page converts better?" With small differences between two variants, the gap in your data ends up bigger than the difference itself. You're testing against noise.
"Do we need more content on topic X?" Hard to say if you don't know how many readers actually converted.

This isn't GA4's fault. It's the consequence of "tracking only with consent." And it happens with every other tool that measures nothing at all without cookie consent.

The ganztags. tracking setup with Matomo cookieless

Open the ganztags. website in your browser's DevTools and check the Network tab, and here's what you'll see:

Matomo Tag Manager loads from https://mt.ganztags.net/js/container_o0zA5JiT.js, immediately on page load, without consent. The container itself doesn't set anything. It only decides what runs.
The first pageview fires to https://mt.ganztags.net/matomo.php before you've clicked anything in the Klaro banner. In the request: _id= (empty), _idn=1, send_image=0. No visitor identifier, no recognition, no cookies. But: the action is counted.
Klaro! as the consent tool. The cookie is simply called klaro and remembers your decision.
Only after accepting do _pk_id.1.a16b, _pk_ses.1.a16b, and mtm_cookie_consent get added, the first-party cookies that let Matomo fully attribute sessions and returning users.
Otherwise, there's nothing else. No google-analytics.com, no googletagmanager.com, no LinkedIn pixel, no Hotjar, no Microsoft Clarity. The only external script: app.varify.io for A/B tests.

That's not a marketing claim. It's the actual content of our tag manager. Before this post went live, we checked it again ourselves. Took 3 minutes.

Why we see every conversion where others lose half

The decisive lever isn't the tool, it's the cookieless pre-consent mode.

Here's how it works for us:

Before the click in the Klaro banner. Anonymized tracking. Truncated IP, no cookie, no visitorId. Matomo sees: "A conversion happened on this page." Matomo doesn't see: "This specific person, who was previously on page X and Y."
After clicking "Accept." Full tracking with first-party cookies. Customer journey, session history, returning users, all of it gets captured.
After clicking "Decline." Pre-consent mode stays active. Conversions keep getting counted, just without any personal identifier.

The point: no conversion falls out of the statistics. Whatever happens in the banner.

What we lose from the people who decline is the customer journey, meaning "which pages did this person see before." What we keep is the ground truth of what actually happened: 25 contact requests through organic search, 12 through LinkedIn, 8 direct. Exactly the numbers you need to allocate budget and attention.

For the visitors who consent, we see the full journey and can trace paths through the site. But we don't make our big decisions based on the sample of people who consented. We make them based on everyone who converted.

Screenshot of the Matomo interface

What cookieless tracking with Matomo actually gets us in reporting

Complete channel attribution. Which channel actually brought in the most leads last quarter, not which one brought the most leads among the people who consented. Sounds like a detail, but for smaller channels, it's exactly the line between "worth it" and "not worth it."
Comparability over time. "We had twice as many demo requests in May 2026 as in May 2025" is a statement, not a rough guess.
A/B tests with enough signal. If half your conversion traffic is missing, a test takes twice as long to reach significance. Ours all run on the full sample.
Honest client reports. "These 47 leads were measured" is a different statement than "these 47 leads are what we could see, plus an estimate of what we couldn't."
A faster site. One Matomo tracking request and one A/B test script. No GTM waterfall sabotaging your Largest Contentful Paint.

Privacy and data ownership are nice side effects. But the real reason we stuck with this setup: the conversion numbers we see on the dashboard every morning are the ones that actually happened.

Where Matomo hits its limits, and why that's okay

Matomo in cookieless mode also means giving up a few features.

Cross-device tracking. Someone reading our blog on their phone on the train and filling out the contact form on desktop that evening counts as two people to us. Full stop.
Audience sync with Google Ads. We can't push remarketing lists or custom audiences from Matomo into Google Ads. Not a problem for us, since we don't run remarketing on our own site. For a shop with a performance setup: a dealbreaker.
Smart Bidding signal. Google Ads optimizes bids based on the conversion data GA4 (or Google Ads itself) feeds back. Matomo doesn't feed anything back. If you run Smart Bidding, you need the other setup.
Out-of-the-box integrations. Hubspot, Salesforce, Marketo, the official connectors are all Google-first. With Matomo, we usually build connections through the Matomo Reporting API ourselves.
"Standard" convenience. Anyone who's ever done online marketing knows GA4. Matomo onboarding takes an afternoon.

We made a conscious choice to accept these trade-offs, because our own website isn't an ads machine. It's a lead source whose mechanics we want to understand. For a D2C shop with five-figure daily revenue, we'd probably decide differently.

Cookieless tracking with Matomo isn't right for everyone

Matomo isn't the right answer for every client. We lean toward GA4 (or a hybrid setup with server-side tracking) when at least one of these applies:

More than roughly €50,000 in monthly performance budget on Google. At that scale, you need the data flow into Google Ads, or you're optimizing against the AI.
International locations with local marketing teams that work in GA4. Tool switches cost more than they save.
An e-commerce setup with GMC, Enhanced Conversions, and Smart Shopping. Harder to pull off without GA4 in the background.
No capacity for self-hosting. Matomo Cloud is an option, but then someone else is hosting it.

Setting up and configuring Matomo in 5 steps

The good news: setting up Matomo isn't complicated. The realistic news: it takes time. Budget one to two days for the technical setup, then a week for migration. If you'd rather skip that time investment, or want support getting the configuration right, we're happy to help with a professional tracking setup.

Set up a Matomo instance. Your own server (PHP, MySQL/MariaDB) or Matomo Cloud. Set up a subdomain like mt.yourdomain.com, add a TLS certificate, don't forget a backup routine.
Use Matomo Tag Manager, not the raw tracking snippet. Saves you every future argument about event tracking and extensions. Tag Manager → Tag → Matomo → enter Site ID → done.
Define conversion goals. Form submissions, demo bookings, newsletter signups, downloads. Before you optimize on data, you need to know what actually counts as a conversion for you.
Integrate a consent tool and activate pre-consent mode. We use Klaro!, because it's open source and lightweight. In the Matomo tag settings: disableCookies on, requireConsent off (so conversions get counted even without consent), setCookieConsentGiven only fires after a click in the banner. IP anonymization on.
Pull comparison numbers. If you're already using GA4, run Matomo in parallel for two to three months. That gives you solid comparison data and shows you how big the gap between "visible in GA4" and "actually happened" really is in your case. Rule of thumb: for B2B sites, usually much bigger than expected.

Conclusion: Data that decisions can rest on

We chose Matomo and cookieless pre-consent because we want conversion numbers that show what actually happened, not a sample of what half our visitors allowed. For decisions about budget, channels, and content, that's the sturdier foundation.

Privacy and faster load times come on top. But if we could only name one reason, it would be data completeness. For your site, that might be the right answer. Or it might not. We can help either way.

Want to know how many conversions are currently invisible to you? Just reach out through our website or message us on LinkedIn. We'll look at your setup together in a free first call and tell you honestly whether switching is worth it for you.

Matomo & cookieless tracking: Frequently asked questions

What is Matomo?

Matomo is a web analytics tool that measures where visitors come from, what they do on your website, and whether they convert.

What's the difference between Matomo and GA4?

GA4 stores your data with Google, is free, and quick to set up. The catch: Google has access. Matomo stores everything on your own server, costs a monthly fee, and gives you full control. Google Ads and Smart Bidding work seamlessly with GA4. With Matomo, you need more manual work.

Who is tracking with Matomo worth it for?

Tracking with Matomo makes sense when privacy and control matter more to you than convenience, so for B2B sites, companies with small ad budgets, and agencies that want to work transparently. It's less ideal if you depend on Google Ads Smart Bidding or your team already knows GA4 inside out.

What is cookieless tracking?

Cookieless tracking captures user behavior without setting a single cookie. Instead of storing an ID in the visitor's browser, tools like Matomo rely on server-side data collection, IP anonymization, and statistical models. The principle: understand behavior without storing identity.

The difference from classic tracking is simple but decisive. A cookie remembers "this one person came back." Cookieless tracking recognizes "someone was here who behaved this way," aggregated, anonymized, with no personal reference.

What are the pros and cons of cookieless tracking?

Cookieless tracking comes with both advantages and drawbacks:

Advantages

More complete data: users who decline cookies disappear from the statistics with classic tracking. With cookieless tracking, they stay visible.
GDPR compliance without a banner: configured correctly, cookieless tracking runs without needing consent. No consent banner, no friction in the user flow. Data flows without you having to ask permission first.

Drawbacks

Cross-device tracking gets harder: without a persistent ID across devices, tracing someone's path from smartphone to desktop only works to a limited degree. A real setback for attribution models with long customer journeys.
Higher technical effort: server-side configuration and clean setup replace the simple cookie snippet you'd just paste in. This setup isn't a five-minute job.

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