The Facebook Conversion API lets you send events directly from your server to Meta’s servers, bypassing tracking issues caused by browser limitations, ad blockers, or iOS privacy updates. As a result, when used alongside the Meta Pixel, you get more accurate tracking and a clearer picture of campaign performance. Furthermore, by setting up CAPI with Zapier, you can automate the process and feed Meta the exact data it needs, in the right format, every time a lead converts — which means your database reactivation lists stay clean and your email marketing compliance stays intact, since you’re not re-targeting contacts who already converted.

Step 1: Prepare Your Form Page

In this tutorial, we’re using Unbounce as the form platform. However, if you’re using JotForm, Leadtook, or any other form builder, the process is similar. First, add a small piece of JavaScript code to your form page to capture the User Agent. This identifies the browser and device of the user. Here’s what to do:

1. Open your form page.

2. Add the GetUserAgent script before the closing body tag.

3. Create a hidden field in your form named user_agent.

4. The script will automatically populate this field when someone lands on the page.

This ensures that when the form is submitted, the User Agent value is passed along to Zapier and eventually to Facebook CAPI.

Step 2: Test Your Form Submission with a Facebook Click ID

Before building your Zap, it’s important to test with a Facebook Click ID (FBC) so you can verify tracking later. To do this:

1. Go to one of your active Meta ads.

2. Click on the ad and copy the URL.

3. Append ?fbclid=XXXX to the end, replacing XXXX with the click ID you copied.

4. Submit your form using this link to ensure the click ID and other parameters are captured.

Step 3: Build Your Zap in Zapier

• Trigger step — In Zapier, select your form tool as the trigger app. For Unbounce, choose “New Form Submission.”

• Connect your account and select the correct form.

• Run a test to pull in a sample submission. You should see the User Agent, Click ID, and any other hidden fields you’ve set up.

Step 4: Hash Personal Data with JavaScript

Facebook requires certain personal data (email, first name, last name) to be SHA-256 hashed before sending. This keeps the data private and helps maintain email compliance across your funnel. To do this:

1. Add a “Run JavaScript” action in Zapier (Code by Zapier).

2. In the input data fields, map:

   • first_name → First Name from your form

   • last_name → Last Name from your form

   • email → Email from your form

3. Paste in your JavaScript hashing code.

4. Test the step and confirm you see the hashed values and a Unix epoch timestamp (required by Facebook CAPI).

Step 5: Send Data to Facebook via Webhook

Now it’s time to send your data to Meta. In other words, this is where the tracking loop closes:

1. Add a “Webhooks by Zapier” action.

2. Set the method to POST.

3. In the URL field, paste your Facebook Conversion API endpoint along with your Pixel ID.

4. Add your Access Token:

   • Go to Facebook Business Manager > Events Manager.

   • Select your Pixel.

   • Under “Settings,” find the Conversions API section and generate an access token.

   • Paste it into your Zap.

Step 6: Map All Required Facebook Parameters

You’ll need to map the following:

• event_time → Unix timestamp from JavaScript step (no quotes)

• event_source_url → The page URL (either hard-coded or from the form)

• user_agent → From the hidden field you created

• client_ip_address → Captured from the form or via additional script

• fbc → Facebook Click ID from form data

• fbp → Facebook Browser ID from form data

• email, first_name, last_name → From your hashed JavaScript step

Optional fields you can add: currency (e.g. GBP or USD), value (monetary value of the conversion), and content_name, content_category, content_ids (for categorising events).

Step 7: Test Your Setup

Before going live, be sure to:

1. Go to Test Events in Events Manager.

2. Copy your Test Event Code.

3. Add it to your webhook request body in Zapier.

4. Send a test and confirm the event appears in Events Manager.

5. Once confirmed, remove the test code from your Zap.

Step 8: Publish Your Zap

Once you’ve verified everything works, publish your Zap. Your Facebook Conversion API is now connected via Zapier and will automatically send events every time a form is submitted — giving you a solid, accurate foundation for any future database reactivation push.