_ga_<IDENTIFIANT> — Google Analytics 4
By the OpenCookies team · published 2026-10-22 · updated 2026-10-22
- Service
- Google Analytics 4
- Category
- Analytics
- Default duration
- 2 years
- Type
- First-party cookie (set by your own site)
- Consent required?
- Yes, in principle: only audience measurement meeting strict conditions can be exempt from consent in the EU.
What is it for?
Stores the session state of Google Analytics 4. Its name contains the property ID (for example _ga_ABC123DEF4).
What does it look like?
The value usually starts with GS1 or GS2, followed by the session start date and a session counter.
How to see it in your browser
Open your site, press F12, then choose the “Application” tab (Chrome, Edge) or “Storage” (Firefox). Under “Cookies”, select your site’s address: the _ga_<IDENTIFIANT> cookie appears in the list if present, with its value and expiry date.
What does the rule say?
Audience measurement in principle requires the visitor’s prior consent. The French CNIL accepts an exemption for some tools configured very strictly (statistical purpose only, no cross-referencing with other data and no cross-site tracking); detailed conditions are on its website.
How to prevent it before the choice
Same method as _ga: the GA4 script must not run before consent.
How OpenCookies handles it
Common services like this one are in OpenCookies’ tracker list: the banner neutralizes their script before the visitor chooses and only restarts it after “Accept”. The test shows whether this cookie appears before the choice, after “Refuse” and after “Accept”.
Step-by-step guide : Google Analytics 4 and cookies: what to do before consent
Check it on my site
Does this cookie appear on your site before the visitor chooses? The OpenCookies test shows it in two minutes.
Related cookies
Frequently asked questions
Why does the name change from site to site?
Because it includes the ID of the Google Analytics 4 property (the code starting with G-). Each property therefore has its own cookie.
Is consent required?
Yes, in principle, as for _ga: it is part of the same measurement system.
Durations are defaults and may change with configuration. This page describes a cookie; it is not legal advice.