Conversion APIs for ecommerce: Meta, TikTok and Google compared
This page puts them side by side. Where each tool sits in the wider ecommerce marketing technology stack is covered on the technologies index.
What do conversion APIs do?
A tracking pixel sends visitor actions from the browser to the platform. A conversion API sends the same kind of event from your side. Meta recommends running the Conversions API alongside its Pixel, a set-up it calls redundant2.
Each platform has its own flavour:
- Meta. CAPI sends events from an advertiser's server, platform, app or CRM to Meta1. Our page on the Meta Pixel and standard events covers the browser half.
- TikTok. TikTok's help centre defines the Events API and recommends running the Pixel and the Events API together, with deduplication3. Setup is covered in TikTok Pixel and Events API setup.
- Google. Enhanced conversions send hashed customer data, such as an email address, to improve conversion matching. The hashing is SHA-256, and Google now combines enhanced conversions for web and leads in one on/off setting4.
- Reddit. Covered in Reddit Pixel and Conversions API setup.
Why do e-commerce brands use them?
Browser tags can miss events. A page fails to load, a script is blocked, a checkout redirects. A server-side route gives the platform a second chance to hear about the sale.
There is a second use. Customer data you hold, such as an email address on an order, can improve matching between the sale and the ad.
Neither use makes the platform's number the truth. A better-fed platform still marks its own homework.
How do we implement it?
Choose the events
Agree which events matter, where they are sent from and which customer fields go with them. Skip platforms you do not spend on.
Settle consent
Someone decides when customer data may be sent. Hashing does not answer that question, and your own lawyer should.
Start with one platform
Begin with the platform that takes most of your ad budget. Use matching event names and IDs on both paths.
Check, then add
Use the platform's quality view, and check deduplication as well as matching. Only then add the next platform.
When should you not use it?
Hold off when you cannot say which events matter, when your consent set-up is unclear, or when browser events are already duplicated. Fix those first. Also skip platforms you do not spend on. Sending events to a channel you are not buying helps nobody.
What does it cost in effort?
No figures here. The effort is mostly people and checking:
- Build. Agree which events you send, from where, and with which customer fields.
- Deduplication. Both paths need matching event names and IDs.
- Consent. Someone must decide when customer data may be sent.
- Checks. Each platform offers a quality or matching view. Use it. Event Match Quality (EMQ) is Meta's score of how well customer details match Meta accounts. It rates matching, not deduplication. Meta's overview asks you to confirm that events are both deduplicated and matched correctly1.
Pitfalls
Double counting
Meta needs the same event ID and event name from Pixel and server, and it deduplicates only within a window of 48 hours2. TikTok requires an event ID when both are used7. Posts in a hosting vendor's forum and in Shopify's community describe duplicate events89. Read our guide to Meta Pixel and Conversions API deduplication, and the event deduplication entry.
Hashing is not consent
Hashed customer data does not remove the consent question. Google's EU user consent policy puts obligations on advertisers in the EEA10. Take legal advice from your own lawyer.
Long sales cycles
Google's GCLID import expects a click-to-conversion cycle shorter than 14 or 90 days, depending on the data source5. Slower conversions do not fit.
Confusing EMQ with deduplication
A good match score does not mean events are counted once.
Treating it as a fix for weak tracking
It adds a route. It does not repair a broken data layer.
Our take: Core, with parts that are not
We rate the topic Core. This is our view, not a market fact. The parts differ:
| Part | Our view | Why |
|---|---|---|
| Meta CAPI | Core | Meta sets out Pixel plus CAPI with deduplication on event ID12 |
| Google enhanced conversions | Core | Google documents it, and web and leads now share one setting4 |
| TikTok Events API | Selective | Worth doing when TikTok is in the mix; TikTok recommends Pixel plus Events API3 |
| Offline upload by GCLID | Watching | For new set-ups, Google's own help recommends enhanced conversions for leads instead5 |
On offline events: Meta's developer changelog announced the discontinuation of its separate Offline Conversions API and recommends the Conversions API for new integrations6. CAPI covers offline events1. Do not build anything new on the old route.
For ZFD: Core for the platforms you already spend on. Selective for the rest. Watching for anything that looks like a legacy route.
FAQ
What is the difference between a pixel and a conversion API?
A pixel runs in the browser. A conversion API sends events from your server, platform or CRM. Meta recommends using both together2.
Do I need both the Pixel and the Conversions API?
Are enhanced conversions the same as CAPI?
Is hashed customer data still personal data?
Treat it that way. Hashing does not remove the consent question for advertisers in the EEA10. Ask your lawyer.
Which one should I set up first?
Our view: the one on the platform that takes most of your ad budget. Then check deduplication before you add the next.
Sources
- Conversions API overview (Meta for Developers)Primary source
- Handling Duplicate Pixel and Conversions API Events (Meta for Developers)Primary source
- About Events API (TikTok Ads Help)Primary source
- About enhanced conversions for web in the Google Ads API (Google Ads Help)Primary source
- Set up offline conversions using GCLID (Google Ads Help)Primary source
- Graph API changelog v20.0 (Meta for Developers)Primary source
- About event deduplication (TikTok Ads Help)Primary source
- Facebook Conversion API - Duplicate Server-Side Events Issue (Stape Community)Forum
- Facebook Pixel / Conversion API Duplicate Events (Shopify Community, styczeń 2022)Forum
- EU user consent policy (Google Ads Help)Primary source
Let’s find what’s actually working.
Next step. Not sure which of these your account needs? Talk to us about your tracking setup. Or see our Analytics & tracking service.