In my experience, most conversations about Meta Conversion API (CAPI) – especially with Meta representatives – tend to focus mostly on improving the Event Match Quality (EMQ) score.
While EMQ is important, I highly recommend looking beyond it to understand how server-side tracking works and what else matters for better data quality.
What is the Conversions API?
Conversions API (CAPI) allows you to send data to advertising platforms directly from your website server, server-side Google Tag Manager (sGTM), app, CRM, or other sources. Most major ad platforms now support their own versions of CAPI, including Meta, TikTok, Google, and Pinterest.
Why Do You Need Server-Side Tracking or CAPI?
Traditional website pixel tracking relies on cookies and browsers. However, modern browsers like Safari and Firefox include Intelligent Tracking Prevention (ITP), which blocks or limits tracking.
These browsers now:
- Block all third-party cookies by default
- Limit the lifespan of first-party cookies (as little as 1 to 7 days) for known marketing trackers
Privacy-focused browsers like Brave block all detected tracking by default.
With server-side tracking, instead of sending data from the browser to analytics or ad platforms, you send it to your server through your own domain, and from there to the destination platforms. This method mimics first-party data flows and helps avoid detection and blocking by browsers or ad blockers.
Safari is already fighting back. If the browser detects that your subdomain (e.g., analytics.yourdomain.com) uses a different IP address than your main domain, it can still restrict cookies.
Besides ITP and ad blocker impact mitigation, there are other benefits for server-side tracking:
- Greater control over what data is sent to platforms
- Reduced client-side scripts, leading to faster page load
- More comprehensive and sensitive data collection, such as profit margins, backend sales or lead status
Facebook CAPI Setup Options
Option 1. Partner Integration (via Plugins or Apps)
This is the easiest option and is available for popular platforms like: Shopify, WordPress, etc.
Pros:
- Easiest to set up with minimal technical skills
- Often free or low-cost via plugins
Cons:
- Limited to predefined events
- Not suitable for customized use cases
This option is suitable for standard e-commerce setups or very basic use cases, but might not fit you if some customization is needed.
Option 2. Manual Integration (via API)
You can implement CAPI directly by sending requests from your server to Meta’s endpoint.
Pros:
- Full flexibility and control
- No additional server cost if using existing infrastructure
Cons:
- Requires ongoing developer resources
This is probably the most complicated option, as you need to ensure that you have developer resources & knowledge both to implement it, as well as monitor and manage the setup.
I had a case where the client’s CAPI tracking broke because their developers did not update the API to a new version.
Choose it only if you know what you are doing, have reviewed other options, and are sure you need to have a manual integration.
Option 3. Google Tag Manager Server-Side (sGTM)
You can use your web Google Tag Manager to send the data to the server-side GTM, where you manage the data and then send it to various ad and analytics platforms.
Pros:
- Supports Meta, TikTok, Google Ads, GA4, and more
- Highly customizable and helps to consolidate all the tracking and data management
Cons:
- Requires sGTM technical expertise
- Involves additional occurring tech costs. Monthly costs range from 20 USD/EUR to 200+, depending on traffic and event volumes, as well as the platforms used
Option 4. Meta CAPI Gateway
CAPI Gateway is a Meta solution that simplifies server-side event tracking. It allows you to configure the Meta website pixel to automatically send the data both to Meta directly, as well as a server with your first-party subdomain, which sends the data to Meta.
Pros:
- Easy to set up without coding
Cons:
- Still relies on the Facebook browser Pixel, which can be blocked
- Less control over data flows
- Additional monthly costs are around 10 EUR/USD or more
Option 5. Meta Signals Gateway
This is the most recent and similar solution to CAPI Gateway. The main difference is that it supports:
- more data input sources in addition to website pixel – file upload, CRM apps, SDK
- more destinations – CAPI, BigQuery, custom endpoints
Pros and Cons are quite similar to the CAPI Gateway, with the addition of support for extra data sources or destinations.
How to Choose the Right Setup
What option to choose depends on several factors, but I usually suggest the following.
Choose Partner Integration or CAPI Gateway if:
- You are a small business
- You run only Meta ads or need CAPI only for Meta
- You need a quick and basic setup
- Your website is built with a popular web platform that has appropriate plugins for CAPI
Choose server-side GTM integration if:
- You want to mitigate ITP impact across all platforms, not just Meta
- You need better customizatoin and data management options
- You have a significant advertising budget
- You have internal or external technical resources with sGTM experience
Common Facebook CAPI Data Quality Metrics
Event Match Quality (EMQ)
Meta assigns each event a score from 0 to 10 based on how well the customer information matches a Meta user. Higher scores lead to better attribution and optimization.
There are multiple data points that you can send to Meta, such as:
- Customer Email
- Customer Phone Number
- Facebook Click ID
- Pixel ID (fbp)
- Customer Name, Surname
- Customer City, ZIP, country
- External user ID
- Customer IP address
- Customer Browser agent string
Usually, the biggest impact is from sending the email, phone, and Click ID. The more data points you have and send, the better Meta will be able to match the event to the specific user and ad campaign.
However, there could be cases where some data points won’t be available, so your match score will be lower. For example, you might not have the customer’s email for the add to cart event, as in your store users submit their emails only during checkout.
Or, your Meta ad traffic share is low, so you will be sending Click ID for a low share of the events, resulting in a lower match quality score. This might lead to constant reminders from your Meta representatives to fix this, while it might not be an issue, but rather just a deviation from Meta average benchmarks and expectations.
Event Coverage
Shows the percentage of browser (pixel) events that are also sent via CAPI. Meta recommends 75 percent or more.
Event Deduplication
Meta recommends sending both pixel and server events, so to avoid double-counting, you should add a unique event ID, which will help to deduplicate web pixel and server events.
With poor deduplication, you might over-report conversion, so you need to monitor this metric.
Data Freshness
Pixel events are sent in real-time. CAPI events can range from real-time to delayed (e.g., batch uploads). The faster, the better.
Server-side hits should be sent at least hourly, CRM integration might have a daily frequency, while this depends both on your technical infrastrucute as well as business type.
Other Key Considerations for High-Quality CAPI Data
First-Party Domain Use and Cookie Lifetime
As mentioned in the beginning, to mitigate ITP impact, you need to send the website events to and set the cookies from the server endpoint within your first-party domain and the same IP as your main domain. This is especially relevant for the setup with the server-side Google Tag Manager (sGTM).
Ask yourself:
- Are you downloading GTM and Pixel scripts from a first-party domain?
- Are you sending data to your server-side GTM via the same domain?
- Is the sGTM server IP the same as your website’s IP?
If not, browsers like Safari may still block or restrict cookies.
If you will be using Manual and Partner integrations, most probably you will be sending the data from the same domain and IP as your website.
While for server-side GTM setup, you have several options:
- Use a CDN or load balancer to proxy requests
- Use your own CDN
- Use Cookie Extender or Cookie Keeper tools from Stape
You can read more about each option here.
Data Privacy Compliance and Tracking Consent
For websites with European traffic, same as for the website pixels, send CAPI events only after receiving user consent to comply with GDPR/ePrivacy regulations. You may also need to anonymize or clean data before sending, especially for sensitive categories like health data (HIPAA compliance).
sGTM allows flexible transformation, giving you control to clean or block sensitive data.
Data Collection and Transformation
Ensure data is accurate and complete, for example:
- Are the purchase value and currency correct?
- Do you enrich data with metadata like customer type (new or returning)?
- Do event volumes seem reasonable?
Infrastructure and Maintenance
If you are using your servers and custom CAPI implementation, you will be responsible for the server response times, API version updates, etc.
The same applies if you are using sGTM deployed on GCP or AWS that you manage.
With the sGTM hosted on services like stape.io, some part of the server management is done on your behalf, but you still need to have (and ensure recurring payments for) an appropriate account plan for your data volumes; manage CDN or load balancer services; ensure proper sGTM and data flow between client GTM, server GTM and destination platforms; etc.
And last, but not least, your website functionality and updates. I’ve seen too many tracking issues due to website updates, using outdated app/plugin versions, compatibility issues, or just developer typos when copying the code.
Final Thoughts
CAPI and tracking setups are often treated as “set and forget” projects. But to maintain quality, you must monitor the data and stay current on browser updates like ITP.
If you actively run marketing campaigns and spend a lot on advertising, investments in server-side tracking and CAPI can significantly improve your campaign performance and data accuracy.
And remember – there’s more to quality tracking than just improving your EMQ score.