Tracking whether your ads actually lead to sales can be messy. Customer journeys can span days, weeks, or months, making it challenging to pull together data from every step. With browser-based tracking facing growing limitations, conversion tracking is harder than ever.
Most businesses today run digital ads, and conversion APIs can simplify conversion tracking while improving data accuracy. This makes it easier to optimize ad campaigns and reduce wasted spend.
In this guide, you’ll learn what conversion APIs are, how they work, and how to implement them in your business to improve ad tracking and performance.
What is a conversion API?
An application programming interface (API) is a tool that lets two different software applications exchange specific data without exposing all their internal code and processes. In other words, it enables application A and application B to communicate and interact in a controlled, purposeful way, sharing only the data needed for the task.
A conversion API, also known as a server-side API, lets a business send marketing data from its servers directly to the servers of an advertising platform. The business shares selected data—product views, purchases, and anonymous customer identifiers—while the ad platform provides data on ad impressions and clicks. By matching these datasets, they can connect ad interactions to actual customer behavior, regardless of browser tracking limitations.
Think of it like using a personal courier. The courier leaves your business (i.e., your server) carrying only the packages you’ve chosen (i.e., your customer and event data) and delivers them straight to the destination (i.e., the ad platform’s server). This direct path avoids any detours or additional pickups (i.e., browser limitations).
Although this could apply to any ad platform in theory, a conversion API is a direct integration you often see discussed in connection with major players like Facebook, Instagram, TikTok, or Google Ads. Depending on your region, APIs may still be required to adhere to data compliance standards and privacy laws like the General Data Protection Regulation (GDPR)—protecting you from potential fines and maintaining customer trust. A website privacy policy can help facilitate compliance.
Key benefits of using a conversion API
Implementing a conversion API delivers three connected advantages for your advertising strategy—each building on the others to strengthen your ad performance. Here are the main advantages:
Direct integration
One of the key benefits of using a conversion API is it makes a server-to-server connection rather than relying on browser-based tracking. This avoids issues like ad blockers, privacy regulations, and restrictions on third-party cookies.
Data accuracy
Since the data comes directly from your server, conversion APIs capture more reliable and detailed information about user actions. This includes product views, clicks, purchases, and server events, such as automated updates. You can also choose exactly which events to track and avoid collecting unnecessary data.
Conversion APIs also help prevent data gaps caused by browser errors, network outages, or slow page loading.
Ad optimization
For all the reasons listed above, conversion APIs can be a powerful tool to help you optimize your ad campaigns. Passing more accurate conversion data on to ad platforms lets them adjust their ad delivery accordingly, reaching users more likely to convert. That’s a compelling recipe for boosting your return on ad spend (ROAS).
Example of conversion APIs in practice
Consider a small rock climbing shoe brand called Piton Collective. The company decides to use the Facebook conversion API to reach potential customers in online climbing groups.
When someone clicks on a Piton Collective ad and visits its website, the Facebook conversion API lets Piton Collective send website data, including purchase and browsing details, directly back to Facebook. Facebook matches this with its own data on which ad the person saw or clicked, confirming that the ad led to a sale. The matched data then feeds back into Facebook’s ad delivery system, helping it improve ad targeting and ROAS over time.
How to set up a conversion API
- Identify relevant conversion events
- Define conversion data parameters
- Set up server-side tracking
- Configure the server-to-server connection
- Verify conversions are matched correctly
The process details of setting up a conversion API may vary by advertising platform, but the steps generally follow the same pattern. It can be helpful to have some coding experience yourself or get help from a programmer to see this process through from start to finish.
However, some platforms streamline and automate the process via partner integration. For example, if you use an ecommerce platform like Shopify, you can use partner integration for setting up the Facebook conversions API.
Here’s what the setup process looks like:
1. Identify relevant conversion events
Start by defining the conversion events most relevant to your business and thus worth tracking. For many ecommerce brands, this might include customer actions such as adding items to a cart, initiating checkout, completing a purchase, or signing up for a newsletter or loyalty program. Some brands might also want to track offline conversions, such as in-store purchases tied to a customer account.
2. Define conversion data parameters
Once you’ve identified your key conversion events, determine the related data you want to send to the advertising platform. Getting this right ensures tracking what drives revenue, so you know which ads are worth the budget.
You may want to include the event ID as well as customer identifiers like email address or phone number, information that should be hashed (made anonymous) before transmission.
3. Set up server-side tracking
Next, set up the destination for your data (a URL or address) required by the specific ad platform being used. For platforms like the Facebook conversion API and Pinterest API, that will require setting up a server-side endpoint: essentially, a dedicated receptacle on the advertiser’s server that will receive the data you send from your business server.
4. Configure the server-to-server connection
Once that server-side tracking is in place, configure your website to capture and send the right conversion data to the right place. Many platforms will generate an API token that can be embedded in your website’s back-end code. This implements the API integration and establishes seamless communication between the two servers.
5. Verify conversions are matched correctly
Once conversion data is being forwarded to the advertiser’s server, take the time to verify that conversion attribution is matched correctly. You’ll want to check that it isn’t duplicating conversion events captured via browser-side conversion tracking or offline events recorded in a CRM.
Conversion API FAQ
What is a conversion API?
A conversion API is a direct integration that lets an organization send its marketing data to an advertising platform like Facebook, TikTok, or Google Ads via a server-to-server connection. This bypasses the browser entirely, creating a more reliable connection.
What is the benefit of a conversion API?
There are several benefits to conversion APIs, the main one being direct integration with the platform you’re advertising on, giving you more accurate marketing data and helping you optimize your online ad campaigns to get the most from your marketing spend.
Which conversion API is best?
The best conversion API can differ depending on the specifics of your business, but the shortest answer is the API for the advertising platform that provides the best return on investment for your ad budget. That may be Facebook, Instagram, TikTok, Google Ads, or something else entirely.
