# What is the Conversions API (CAPI)?

> Meta's Conversions API sends purchase and lead events from your server to Meta, so fewer sales go missing. What it is, why it matters and how to set it up.
- **Author**: Marxx
- **Published**: 2026-10-21
- **Category**: Meta
- **URL**: https://marxx.ai/library-glossary/conversions-api

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The Conversions API (CAPI) lets your website's server tell Meta when someone buys, signs up or adds to cart. The Meta Pixel does the same job from the shopper's browser. CAPI is the backup that still works when the browser blocks the pixel.

## Why the pixel alone misses sales

- Ad blockers and some browsers block tracking scripts.
- iPhone privacy settings limit what apps and sites share.
- Slow pages close before the pixel fires.

Each missed event is a sale Meta never learns about. It then optimises on less data.

## A worked example

Say a store gets 1,000 orders in a week. Its pixel reports 720 of them to Meta. After adding CAPI, Meta receives 940, with duplicates removed.

Meta now sees 220 more buyers to learn from. Reported cost per purchase drops, partly because the sales were always there and Meta simply was not told.

## Pixel and CAPI together

Meta recommends running both. Send the same event from each with the same event name and event ID. Meta keeps one copy and drops the duplicate. This is called deduplication.

## How to set it up

| Your setup | Easiest route |
|---|---|
| Shopify | The Facebook & Instagram sales channel, with data sharing set to Enhanced or Maximum (Shopify's help page, checked 2026-10-20) |
| WooCommerce | Meta's official plugin, which has the Conversions API built in |
| Custom site | Meta's Conversions API Gateway, or a server-side tag manager |

After setup, check **Events Manager**. Look at Event Match Quality, a score from 1 to 10 for how well your events match Meta users. Meta suggests aiming for 6 or higher. Sending hashed email and phone numbers raises it.

## FAQ

### Is CAPI only for big brands?

No. Any account that sells online gains from it, and most store platforms now offer it free.

### Does CAPI break privacy rules?

You send hashed customer data, and you should cover it in your privacy policy and consent flow. Check the rules for each market you sell in.

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