---
title: "First-Party Server Tagging"
category: studio-standards
status: recommended
url: https://webspecification.com/spec/studio-standards/first-party-server-tagging/
source_repo: undefined
licence: CC-BY-4.0
---

# First-Party Server Tagging

> Engineering data architectures that bypass third-party cookies using Server-Side tracking.

## What is it?

Server-Side Tagging is a data collection architecture where the user's browser sends analytics events directly to a first-party server (e.g., `metrics.yourdomain.com`). That server then processes, sanitizes, and forwards the data to third-party vendors (Google Analytics, Facebook, Mixpanel) server-to-server.

## Why does it matter?

Client-side ad blockers, Safari's Intelligent Tracking Prevention (ITP), and privacy extensions block third-party trackers, resulting in up to 30% data loss for marketers. Server-Side tracking bypasses these blockers because the requests go to your own first-party domain. Furthermore, it vastly improves security and privacy, as you can strip out PII (Personally Identifiable Information) before forwarding the data to Big Tech.

## How to implement it

### 1. Server-Side Google Tag Manager (sGTM)
Deploy an sGTM container on a subdomain you control. 

1. The client-side code sends an event to `https://metrics.yourdomain.com/collect`.
2. The sGTM container receives the event.
3. The container sanitizes the IP address and strips URL parameters.
4. The container dispatches the data to Google Analytics and Meta Conversions API.

## Verification

- Inspect network traffic on your site. All analytics requests must be routed to a subdomain of the site you are currently visiting, not directly to `google-analytics.com` or `facebook.com`.