Facebook Conversion API vs. Facebook Pixel

Dec 30, 2022
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A lot of you have heard about Facebook Conversion API and Facebook Pixel. Though they sound similar in name, these two tracking methods work differently. Both tools provide crucial insights into how users interact with websites, but they collect data differently — making it important for businesses to distinguish which one is right for their needs.

In this blog post we’ll describe features of Facebook Conversion API and Facebook Pixel, compare them and discuss their setup. 

What is Facebook Pixel

Facebook pixel is a data-gathering tool that can help you make the most of your Facebook and Instagram advertisements. Basically, Facebook Pixel, or now Meta Pixel, is a script that you put in your website code. 

It collects data that allows you to analyze Facebook ad conversions, optimize advertisements, generate targeted audiences for future ads, and remarket to people who have already made some form of action on the website.

It helps companies to evaluate the effectiveness of their product or service advertising. Pixel tracks what users do when they come to your website after clicking an ad, as well as the pages they visit. 

How Facebook Pixel works

Facebook Pixel places the cookies and triggers them to track users. Everything is happening in the visitor’s browser. And that’s why this method is called client-side tracking

It's also an example of third-party tracking, as data is provided to a third party (Facebook) that your visitor may be unaware of. Browsers are attempting to block third-party tracking.

facebook pixel

What is Facebook Conversion API and what does it do

Facebook Conversion API (CAPI) is a server-side method for tracking FB events. It gives greater data quality and control over the information you track compared to a Facebook pixel. 

Facebook unveiled its Conversion API as a response to tracking restrictions that became more popular during the last couple of years. They state that CAPI s a powerful solution for advertisers looking to accurately measure the response and success of their FB ad campaign and helps counter new tracking restrictions like Intelligent Tracking Prevention in Safari or Firefox that limit cookie lifetimes, iOS tracking regulations, and growing ad-blocking rates.

Recent studies show advertisers can lose up to 30% of conversion data because of ad blockers and tracking restrictions. If these tracking restrictions are enabled, Facebook pixels do not work. This means that FB does not receive valuable information about user actions on the site, which can negatively affect campaign success measurement and the quality of custom and lookalike audiences. 

With Facebook conversion API, you can bypass all these tracking restrictions and track user behavior even when tracking restrictions are enabled, and FB pixel is blocked. How is it possible? 

All because FB CAPI works not inside the user's browser but on the server. Only you can control what user or event data is sent through servers. AdBlockers or ITPs can not access data on the tagging server that sends information to FB using CAPI technology. 

Another considerable benefit of FB CAPI is that it uses 1st party cookies, while FB pixel relies on 3rd party cookies. Every time a user from your FB ad campaign visits your website, FB sets two types of cookies: fbp (browser ID) and fbc (click ID). These cookies are set from the domain and are considered as 3rd party (since it was not your domain that set those cookies). When the user returns to your website and converts, FB uses fbp and fbc cookies to attribute users to the campaigns.

Due to ITP, the lifetime of such 3rd party cookies is decreased to 1 or 7 days. If a user clicks your ad and returns in 7 days to make a purchase, FB pixel won’t see fbc and fbp cookies since ITP erased them. In the end, even though FB pixel might track this conversion and show it in the FB events manager, it won’t be attributed to the FB campaigns responsible for driving the conversion.  

Facebook conversion API can set 1st party cookies when tagging server URL is located on your domain. In this case, fbp and fbc cookies are set from your domain, considered 1st party, and live up to 2 years. It has a massive benefit on FB campaign attribution. 

The last benefit is the ability to send offline events using FB Conversion API. Let us say your business receives a considerable portion of orders by phone. Some of these orders can be driven by FB campaigns. FB pixel can not track which user saw your FB ad campaign, clicked on the ad, and then made a purchase by phone. 

With FB CAPI, you can send offline events in real-time. FB can attribute such offline sales to FB campaigns by utilizing user parameters. The more information about your users you send to FB, the more significant changes they will be able to attribute offline sales to FB campaigns. 

How is the Facebook Conversion API different from the Facebook Pixel

CharacteristicsFacebook PixelFacebook Conversion API
Type of trackingclient-side trackingserver-side tracking
Customer’s journeyFullFull
Offline event trackingNoYes
Ad blockers resistanceNot resistantResistant
Cookies3rd party1st party
Data controlLowHigh

Facebook pixel and Conversion API

Facebook strongly recommends to use both - Pixel and CAPI, to get the most relevant data. But if your site sends the same events using both the pixel and Conversions API, events may be duplicated since FB will receive the same information from the browser and the server.

Facebook has a deduplication feature. They can keep only one if they know that the browser and the server events are identical. 

In our blog, we have an article on the configuration of Facebook Conversion API, and you are welcome to get more details on the setup there.

The main reason is that combining the browser+server method will give you two data sources. And basically, two are better than one. But make sure to set up event deduplication properly. Otherwise, you might face overreporting.


We hope this article sheds some light on Facebook CAPI and Pixel differences for you. If you need help setting up or using Facebook conversions API, please don't hesitate to contact Stape support. We're here to help you get the most out of this great tool.

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