What is a Facebook CAPI Solution?

What is a CAPI Solution?

Facebook Conversion API (CAPI) solutions are services or plugins that track users on your site and send the data to the Facebook Conversions API. Many CAPI solutions automatically collect user data, such as names or emails. This is hard to set up by hand, but can improve your conversion rate and marketing return-on-investment.

Most CAPI solutions are simple to set up, but this ease-of-use can be deceptive. In our testing, we found that the CAPI solution landscape is varied and treacherous. Some solutions only track a handful of predefined events; some don’t provide options to configure the data they collect; and (worst of all) some solutions drop events at random.

Simplicity, flexibility, reliability: choose two.


Apple led the war on analytics with their iOS 14 privacy-focused update in 2021. Since then, tech companies have made a slew of privacy-focused updates. Even advertising giant Google joined in, first with FLOC and then with the Topics API. In 2022, Facebook’s stock finally took the hit, tumbling 22% in a single day. With these seismic shifts, you’d be forgiven for thinking that analytics and tracking is on the way out —

— but you’d be wrong.

Launched in 2020, the Facebook Conversions API (CAPI) provides a foolproof way for marketers to collect the data they need. Server-based CAPI solutions bypass all anti-tracking measures, including adblockers and iOS14.5. On their official blog, Facebook reports that CAPI improves attribution by 25-35% and return-on-investment by a stunning 150%.

The data is clear: If you’re not on CAPI, you’re missing out.

What to Look for in a CAPI Solution

An ideal CAPI solution should:

  • Be easy to set up
  • Be flexible enough to add custom conversion tracking to any webpage element
  • Let you customize the data sent to Facebook
  • Automatically capture user data
  • Load quickly
  • Send data reliably
  • Bypass blockers

These are the major markers of an effective CAPI solution. Installing a solution that’s missing too many of these criteria can result in data loss, reduced SEO ranking, and even legal violations. At the end of the day, a quality CAPI solution maximizes your Facebook match rating. That, in turn, leads to better attribution, which translates to more bang for your advertising bucks.

What is Deviate Tracking?

Deviate Tracking is an affordable, simple-to-use, serverless CAPI solution. Designed from the ground up for flexibility and performance, Deviate Tracking is our answer to Apple’s ultimatum. It’s not just for software engineers, either. Our service integrates seamlessly with Google Tag Manager (GTM), empowering non-technical marketers and analysts to track all their users, including those on incognito and iOS14.5.

CAPI’s Instability

Early versions of CAPI were notoriously unstable. Over the past two years, marketers have struggled to keep up with a seemingly-endless litany of breaking changes. Even now, Facebook frequently updates CAPI with no notice. Documentation is sparse and often out of date. Facebook’s Events Manager has almost no data transparency. As anyone who’s built one can tell you, maintaining a custom CAPI solution is a thorny problem — but that doesn’t mean it has to be your problem.

When new issues arise in CAPI, our engineering team starts with a behind-the-scenes compatibility patch. These patches require no action by our users and resolve the problem in the vast majority of cases. More rarely, we release a new GTM template and notify our customers by email. Updating the template typically takes under five minutes.

When we created Deviate Tracking for our own use, it was one of the first CAPI solutions on the market. Now, over a year later, the industry is catching up. Alternative solutions have grown in popularity and include several official partner integrations as well as a slew of cloud-based offerings.

Testing Deviate Tracking

With so many new CAPI solutions, we wanted to make sure Deviate Tracking was a worthy competitor. To do so, we devised objective tests that pitted Deviate Tracking against half a dozen other common solutions. Competitors included a mixture of cloud services and partner integrations. The results surprised even us.

The Testing Structure

Our goal was to maximize accuracy and thoroughness. Thus, our approach combined real websites and controlled “laboratory conditions”. Real-world tests were conducted simultaneously, to avoid random traffic fluctuations muddling the data.

For our controlled tests, we installed one solution at a time and performed manual tests on a hidden URL that nobody else could access. We linked each solution to a different Facebook Pixel, allowing us to compare the different options and see which was best.

Our Discoveries

Our tests proved that Deviate Tracking is more effective than most other CAPI solutions. Deviate Tracking allowed for more data control and trigger flexibility. It eliminated plugin, theme, and app conflicts, which were common among its competitors. With its advanced features, Deviate Tracking even works alongside many platform integrations. An example of this is Shopify. A heavily-customized Shopify site may not automatically track all the events it should, and Deviate Tracking can fill in the gaps.

We designed Deviate Tracking to be flexible and user-friendly. While it can still be blocked (since it does have a small amount of browser-facing code), we found that Deviate Tracking performs over 58% better than the Facebook Pixel alone. It was also more reliable and accurate than many of Facebook’s partner integrations. 

WordPress and Woocommerce

Approximately half the world’s websites are built on WordPress or Woocommerce. Both platforms have first-party CAPI solutions. Unfortunately, their performance was lackluster when compared to Deviate Tracking.

The WordPress CAPI solution states on its plugin page that it “includes support for the Conversions API”. We were able to thoroughly debunk this claim — no server events were sent from the WordPress solution across all of our tests. This goes to show the importance of testing your CAPI setup (something Deviate Tracking makes easy). Just because a service claims to do something doesn’t mean it will actually follow through.

Woocommerce’s CAPI solution did send server events, but it only tracked events on the Woocommerce shop pages. This had the natural consequence of missing the vast majority of potential events, many of which take place on non-Woocommerce pages.

“100% Accuracy” Fallacy

Many CAPI solutions claim to be “100% accurate”. This is (almost) always impossible. Any solution that runs in the user’s browser can be blocked or fail to execute before the user navigates to another page. The only solutions that can live up to a claim of 100% accuracy are DNS or server level solutions. And in our research, aside from manual individual configuration by webmasters, the only solution we found on the market is discussed below.

The “Best” CAPI Solution with a Catch: Cloudflare Zaraz

Not to be confused with Zara Beauty, Zaraz is a server-side analytics tool offered by Cloudflare. It supports custom events and integrates well with pre-existing tracking, but its killer feature is its ease-of-use. Unlike traditional server-based CAPI solutions, Zaraz features a one-click install in Cloudflare’s dashboard.

As with all server-based CAPI solutions, Zaraz is difficult-to-impossible for end users to block. In our performance tests, Zaraz was the top star with zero data loss for basic page view events. More complex events (such as user interactions) require a small amount of client-side code and can be blocked. However, in practice, this wasn’t an issue. Zaraz is relatively new, difficult to block, and isn’t on the radar for most privacy tools.

Despite Zaraz’s outstanding performance, it’s infeasible in many scenarios. Zaraz is only available as part of a Cloudflare subscription and requires only works on websites run through Cloudflare’s proxy.  Cloudflare’s subscriptions can be very expensive and not every business is going to be okay with using them. However, if you’re already on Cloudflare, or if you don’t mind switching to them, then Zaraz is the #1 CAPI solution.

What is the “Right” CAPI Solution for You?

A custom server-based CAPI solution is by far the most powerful tracking method. It’s reliable, performant, and flexible. You can choose what data gets sent to Facebook, and track arbitrary user interactions with zero risk of blocking. Unfortunately, that power comes at a cost: time.

Implementing a custom CAPI solution is time consuming because it has to be tailored to the specificities of the website. Furthermore, many businesses use locked-down managed hosting. Such hosts typically don’t allow their users to add any complex features, let alone custom CAPI.

Even if your business can, theoretically, write an in-house tracking tool, it may not be cost-effective. Software engineers are expensive, and their time is better spent creating features that bring in new users. That’s why we recommend Deviate Tracking.

Deviate Tracking strikes a balance between simplicity, flexibility, and reliability. It can run on any website that GTM is installed on, and it only costs $19/month. We created Deviate Tracking to satisfy our own needs. Let it satisfy yours too.