What is the Meta Conversions API, and does my Shopify store need it?
By the HonestTag team ยท Published October 24, 2026
The Meta Conversions API sends conversions, such as purchases, to Meta from a server, while the Meta pixel sends them from the shopper's browser. Meta recommends running it alongside the Meta pixel, and removes the second copy of an event when both carry the same event name and event ID, go to the same pixel and arrive within 48 hours of the first copy. On Shopify, the Facebook & Instagram app already uses it at its Enhanced and Maximum data-sharing levels. It helps when a browser drops events. It does not override a shopper's consent choice, and it does not make Meta's numbers match your orders on its own.
What it is
The Meta pixel reports what a shopper does from inside their browser. The Conversions API reports the same kind of event from a server. Meta describes it as a connection from "an advertiser's server, website platform, mobile app, or CRM to Meta systems that optimize ad targeting, decrease cost per result and measure outcomes," and says server events "are processed like events sent using the Meta Pixel" (Meta for Developers).
This article is about the purchase event. If Meta never hears about a sale, it cannot report it.
Install HonestTag free and run the Mirror plan beside your current tracking. It sends no purchases or conversions to your ad platforms, so it cannot double-count a sale or change your current setup, and it shows which platform claims hold up against the new customers in your real orders. Free at any store size.
Why the pixel alone misses purchases
- Browsers block and drop events. Meta says the pixel "relies on browser data, which can be blocked or lost due to browser settings or connectivity issues" (Meta Business Help).
- Pages fail to load. Meta says the Conversions API "can capture website events that the pixel might miss due to network issues or page loading errors" (Meta Business Help).
- Ad blockers. Shopify says that with its Meta connection at Standard, "A browser-based ad blocker can prevent the Meta pixel from sharing data" (Shopify Help Center).
What Meta asks for
- Run both. Meta writes: "we recommend that advertisers implement the Conversions API alongside their Meta Pixel," which it calls a "redundant setup" (Meta for Developers).
- Give both copies the same event name and event ID. When the browser and server send the same event name and event ID to the same pixel "within 48 hours, we discard the subsequent events" (same page).
- Send it soon. An event can be "up to 7 days" old; if any event in a request is older, Meta returns an error for the entire request and processes none of it (server event parameters).
- Send customer details Meta can match. Meta scores event match quality "from 0 to 10" and rates email and click ID as high-priority details (About event match quality). Meta event match quality, explained covers why a score drops.
What your Shopify store may already do
Shopify's Facebook & Instagram app has three data-sharing levels: Standard, Enhanced and Maximum. Shopify says that at Enhanced, "your store uses Facebook's Conversions API as well as the Meta pixel. The Conversions API sends the purchase event between Shopify and Facebook servers." At Maximum, Shopify says the store "uses Facebook's Conversions API, Meta pixel, and is updated with Facebook's latest advertising technology" (Shopify Help Center).
So the first question is not "how do I add the Conversions API?" It is "what level is my store on?" At Enhanced, Shopify says the purchase event already goes server to server.
Check Meta's claims against new customers. The free Mirror plan puts what Meta reports beside the new customers whose first ad click or ad-tagged link was Meta's, and paid plans send verified orders to Meta.
What to check, in order
- Your data-sharing level. In Shopify admin, open Sales channels, Facebook & Instagram, Settings, then Data sharing settings.
- How many tools send Meta a Purchase. Two tools that send the same purchase without matching event names and event IDs can give Meta two purchases. Duplicate purchase events walks through it.
- A pixel pasted into your theme. A second Meta pixel in theme code can be a second purchase source.
- Match quality on the Purchase event. Meta says event match quality "is available for website events sent through the Conversions API with the action source parameter set to Website" (About event match quality).
- Meta's purchases against your orders. Compare the same days. A gap is normal (here is why); a gap you cannot explain is the thing to fix.
What the Conversions API does not fix
- Consent. Shopify says server pixels "are still subject to your store's customer privacy and consent settings" and "If a customer hasn't consented to tracking, then events might be restricted" (Shopify Help Center). Sending from a server does not lift that limit.
- Late events. Past 7 days, Meta returns an error for the entire request and processes no events.
- A bad setup. Two purchase sources without matching event names and event IDs can count a sale twice.
What HonestTag does
- The free Mirror plan sends Meta no purchases. It puts what Meta reports beside the new customers whose first recorded ad click or ad-tagged link was for Meta, counted from your own orders.
- On a paid plan, verified orders go to Meta through the Conversions API once Meta is connected, within the consent rules, each purchase with one order-scoped event ID, so a retry from HonestTag never adds a second purchase.
- Your current setup and HonestTag's Purchase. HonestTag sends its own HonestTag_ events, which do not add to your Meta Purchase count. Meta's standard Purchase starts on only when you tell HonestTag you don't use the Facebook & Instagram app or its data sharing is off. At Standard, or if you are not sure, it goes only when you turn it on and confirm nothing else sends Meta purchases. At Enhanced or Maximum it stays off.
- Each order shows whether Meta received it. A delivery that fails is retried, and an alert goes up when it cannot get through.
The steps and everything sent are on Connect Meta. For the bigger picture, read what a conversions API is and server-side tracking.
Frequently asked questions
Do I need the Conversions API if I use Shopify's Facebook & Instagram app?
Check its data-sharing level first. Shopify says the store uses Meta's Conversions API as well as the Meta pixel at Enhanced, and both at Maximum. At Standard, Shopify describes a Meta pixel collecting data from browsing in your store.
Will the Conversions API count my purchases twice?
Not when the browser and server copies carry the same event name and event ID and reach the same pixel within 48 hours: Meta says it then discards the subsequent events. Two tools sending purchases without matching event names and event IDs can count a sale twice.
Does the Conversions API get around ad blockers?
Shopify says data sent from server to server can't be blocked by browser-based ad blockers. It does not get around a shopper's consent choice.
What is event match quality?
A score from 0 to 10 that Meta calculates for website events sent through the Conversions API with the action source set to Website, based on the quality of the customer information sent and the percentage of event instances matched to Meta accounts. Meta uses the last 48 hours of data.
Check Meta's claims against new customers
The free Mirror plan puts what Meta reports beside the new customers whose first ad click or ad-tagged link was Meta's, and paid plans send verified orders to Meta.
- No risk to your setup. The Mirror plan sends no purchases or conversions to your ad platforms, so it cannot double-count a sale or change your current setup.
- Claims against real orders. It shows what Google Ads, Meta, Microsoft Advertising and TikTok claim beside the new customers whose first recorded ad click or ad-tagged link was that platform, counted from your own orders.
- Free at any store size. The Mirror plan stays free whatever your sales.
Related reading: what a conversions API is, and duplicate purchase events.