Server-side tagging (sGTM)
Server-side tagging runs your tag manager on a server you control, so events reach ad and analytics platforms from your infrastructure instead of the visitor's browser.
In practice this means running a server GTM (sGTM) container in your own cloud, usually on a subdomain of your site. The page loads one lightweight script that sends events to your server; the container forwards them to Google Ads, Meta, GA4, and the rest. No per-platform scripts in the browser.
#sGTM vs server-side tracking
Server-side tracking is the outcome: events delivered server-to-server. Server-side tagging is one way to build it: a routing layer you host and maintain yourself. You gain control over what each platform receives; you take on cloud infrastructure and a container someone has to run. Managed pipelines and Meta's one-click CAPI get smaller setups most of the same durability without the overhead.
Setup, real costs, and the cases where sGTM isn't worth running are covered in Server-side tagging with sGTM: setup, costs, and when it's not worth it.
Related terms
Conversions API (CAPI)
The Conversions API is Meta's server-to-server channel for conversion events: a second delivery route for the same events the pixel sends from the browser.
Server-side tracking
Server-side tracking sends conversion and analytics events from a server you control instead of the visitor's browser: a more durable route for the same events.