- The Conversions API sends events to Meta from your server, platform or CRM, alongside the browser-based Meta Pixel.
- Running both gives Meta more complete data; deduplication with a matching event_id and event_name stops double counting.
- Meta deduplicates matching events only when they arrive within 48 hours of the first one.
- Store platforms and Events Manager offer no-code setups; custom sites and CRMs can send events through server-side tagging or the API directly.
Do you need the Meta Conversions API?
Yes, if you run Meta ads and care about measuring results accurately: the Conversions API sends conversion events from your server, store platform or CRM, filling gaps the browser-based Pixel misses, and Meta deduplicates events that both report. Browser restrictions, ad blockers and consent choices all reduce what a Pixel alone can see. Adding a server-side source gives Meta's delivery system better data to optimize with, and gives you more reliable reporting.
This guide covers what the API does, how deduplication works and the realistic setup options, as we handle them in our Meta and social ads work.
What is the Conversions API?
Meta describes the Conversions API as a way to connect marketing data from an advertiser's server, website platform, mobile app or CRM to Meta, to help optimize ad targeting, decrease cost per result and measure outcomes (Meta for Developers: Conversions API). The Pixel runs in the visitor's browser; the Conversions API sends the same kinds of events, such as Lead, Purchase or CompleteRegistration, from a system you control.
Why run it alongside the Pixel?
Each source has blind spots. The Pixel can be blocked or limited in the browser; a server event can lack browser details such as cookies. Sending both gives Meta two chances to receive each important event and more information to match it to a person who saw an ad. If you already have a Pixel, Meta offers a way to add the Conversions API for website events from Events Manager with no code, configuration or setup fees (Meta for Developers: Conversions API).
How does deduplication work?
If the Pixel and the server both report the same purchase, Meta needs to know it is one purchase, not two. It matches them when two values agree: the Pixel's eventID matches the Conversions API's event_id, and the Pixel's event name matches event_name. Events are only deduplicated if they arrive within 48 hours of the first event with that ID (Meta for Developers: deduplication).
In practice, generate one unique ID per conversion, such as the order number or a lead ID, use it in both the browser event and the server event, and keep the event names identical. Most broken setups we audit either send different IDs or none at all.
What customer information should you send?
Server events are matched to people using customer information parameters such as email, phone number, name and location, plus browser details when available. Contact details are normalized and hashed before sending, as described in Meta's customer information parameters documentation. Send only what you collected legitimately, and the more accurate matching data you include, the better Meta can connect the conversion to an ad.
Which events should you send?
Send the events that match your business goals, using Meta's standard event names so reporting and optimization recognise them:
- Online stores: ViewContent, AddToCart, InitiateCheckout and Purchase, with the order value and currency on purchases.
- Lead generation: Lead when a form is submitted, plus a later event from your CRM when a lead is qualified or becomes a customer.
- Bookings and sign-ups: Schedule or CompleteRegistration when someone books or creates an account.
Fewer, accurate events are better than many noisy ones. Every event you send should mean the same thing every time, so Meta's optimization has a clear signal to learn from.
How do you set it up?
- Store platforms. Shopify and WooCommerce have Meta integrations that send server events for purchases and other store actions. Our Shopify development team checks these are configured correctly, with deduplication.
- Events Manager. For websites with a Pixel, Meta's built-in setup can add server events without code.
- Server-side tagging. A server-side Google Tag Manager container can forward events to Meta and other platforms from one place.
- Direct API integration. Custom websites, apps and CRMs can call the API directly, which is the most flexible option for sending later events such as qualified leads.
Why send CRM events for lead generation?
For service businesses, a form fill is only the start. Sending a later event when a lead becomes qualified or turns into a sale, with the same customer information, helps Meta learn which people become customers. Lead campaigns then optimize towards quality instead of volume. This needs your CRM to record the stage change and an integration to send the event, which our analytics and reporting service sets up.
How do you check it is working?
- Open Events Manager and confirm events arrive from both the browser and the server.
- Check that deduplication is working: the same purchase should not appear twice.
- Review the event match quality score and improve the customer information you send if it is low.
- Test with a real conversion and follow it through to the ad reporting.
How does consent fit in?
Server-side events do not bypass privacy rules. Explain the data sharing in your privacy policy, collect consent where the law requires it, and make sure your server only sends events for people whose choices allow it. A cookie banner that controls both browser tags and server events keeps the setup consistent.
Frequently asked questions
Does the Conversions API replace the Meta Pixel?
No. Meta's recommended setup uses both: the Pixel in the browser and the Conversions API from your server or platform. Each catches events the other may miss, and deduplication makes sure a purchase reported by both is counted once.
Is the Conversions API only for online stores?
No. Lead generation businesses benefit too, especially when they send later events from a CRM, such as a qualified lead or a closed deal. That tells Meta which ads bring real customers, not only form submissions.
Do I need a developer to set it up?
Not always. Shopify and WordPress plugins and the setup options in Meta Events Manager cover many websites without code. Custom websites, apps and CRM events usually need server-side tagging or a direct API integration, which is a developer task.
What about privacy and consent?
Customer details sent through the Conversions API are hashed, but you still need a privacy policy that explains the data sharing and consent where the law requires it. Respect each visitor's cookie choices for browser events, and only send server events for people who agreed where consent is required.
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