Meta recommends sending events through the Conversions API as well as the browser pixel. There are several ways to do that, and two come up in almost every conversation: Meta's own Conversions API Gateway and server-side Google Tag Manager. Both send server events to Meta. They differ in scope, control and how much work they take.
What is the Conversions API Gateway?
The Conversions API Gateway is Meta's no-code option for sending server events. You create it from Events Manager, and it is deployed into a cloud account, usually AWS, either your own or one run by a Meta partner. Once connected to your pixel, it copies the events your pixel sees and sends them to Meta from the server.
- Platforms: Meta only.
- Setup: guided from Events Manager, with the cloud resources created for you.
- Cost: Meta does not charge for the software, but you pay for the cloud hosting or a partner's hosted plan.
What is server-side GTM?
Server-side Google Tag Manager is a server container that receives events from your website (and other sources) and sends them to any platform you configure: Meta Conversions API, Google Ads, GA4, TikTok, Pinterest and more. It runs on Google Cloud or a managed host such as Stape. If you are new to it, read what server-side tracking is.
- Platforms: any platform with a server tag.
- Setup: more configuration, usually done by a tracking specialist.
- Cost: the hosting, which on Stape starts with a free tier. See Stape vs Google Cloud Run.
Side-by-side comparison
| Conversions API Gateway | Server-side GTM | |
|---|---|---|
| Sends data to | Meta only | Meta, Google Ads, GA4, TikTok and others |
| Setup effort | Low, guided | Medium to high |
| Hosting | AWS (yours or a partner's) | Google Cloud or Stape |
| Control over parameters | Limited | Full |
| Add CRM or checkout data | Limited | Yes |
| Offline and CRM events | Not its purpose | Yes, with extra setup |
| Consent handling | Follows the pixel | Fully configurable |
| Best for | Meta-only advertisers who want it simple | Businesses on more than one ad platform |
Data quality: where the difference shows
The biggest practical difference is what you can add to each event. The Gateway mostly sends what the browser pixel already collected. With server-side GTM, you can add hashed email and phone from the checkout, the order ID, the exact value and your own customer IDs before the event reaches Meta. That usually means better Event Match Quality and more conversions matched to ads.
Both options still need correct deduplication. The pixel and the server must send the same event_id for the same action, or Meta counts it twice. I explain how in Meta CAPI event deduplication.
When the Gateway makes sense
- You advertise only on Meta and do not plan to add Google Ads or TikTok.
- You want server events running quickly without a developer.
- A partner offers it as a managed service you are happy to pay for.
When server-side GTM makes sense
- You run Google Ads and Meta (most of my clients do), or plan to add other platforms.
- You want to enrich events with checkout or CRM data.
- You want one place to control consent, data and every destination.
- You need offline conversions, such as leads that become customers later.
My recommendation
For most businesses I work with, server-side GTM is the better long-term choice, because one container feeds every ad platform with the same clean, deduplicated data. That is the setup behind projects like Respivox and Histro Clothing.
The Gateway is a fair choice for a Meta-only advertiser who wants something simple. Just avoid running the Gateway and a second server setup for the same events, or purchases may be counted twice.
Not sure what your site uses today? Run it through the free Tracking Checker, or read Meta Pixel vs Conversions API for the basics.