How to Find the Measurement ID in GA4

Updated: January 3, 2026

What Is a Measurement ID?

In Google Analytics 4 (GA4), a Measurement ID is a unique identifier used to define a specific data stream within a GA4 property.

Its main purpose is simple:

It tells GA4 where your data should be sent.

In other words, the Measurement ID acts as the entry point for data collection for a specific web or app stream.

Each web data stream in GA4 has its own Measurement ID.

Measurement ID Format

A GA4 Measurement ID always follows this format:

G-XXXXXXXXXX

Key characteristics:

• Always starts with “G-”
• Followed by a unique combination of letters and numbers
• Assigned per Web Data Stream
• Cannot be reused across different streams

Example:

G-1A2B3C4D5E

GA4 Measurement ID vs Universal Analytics Tracking ID

If you’re migrating from Universal Analytics (UA), it’s important not to confuse the two.

Key takeaway:

GA4 Measurement ID identifies a data stream, not the entire property.

Where Measurement ID Fits in GA4 Architecture

GA4 follows this hierarchy:

Account
 └── Property
      └── Data Stream (Web / App)
            └── Measurement ID

• A single GA4 property can contain multiple data streams
• Each stream has its own unique Measurement ID
• Web, iOS, and Android tracking each use different IDs

How to Find the Measurement ID in GA4

In GA4, follow these steps:

1、Go to Admin in GA4：

2、Under Data collection and modification, click Data Streams：

3、Select your Web Data Stream：

4、In the stream details page, you will see the Measurement ID：

It will look likeG-XXXXXXXXXX，This is the ID you will use for implementation.

Reference

• Google official documentation: https://support.google.com/analytics/answer/12270356