Cookie reference · Google Analytics

The _ga_<container-id> cookie

A Google Analytics 4 cookie that keeps session state, such as the session ID and session count, for one GA4 property on the site.

_ga_<container-id> at a glance

Cookie name: _ga_<container-id>
Vendor: Google Analytics
Category: Analytics
Party: First-party
Typical duration: 2 years
Set on: .<your-domain>
Value format: Opaque session-state string, commonly starting GS1. or GS2. (format not documented by vendor)
Name match: Any cookie whose name starts with _ga_

What the _ga_<container-id> cookie does

GA4 sets one of these per measurement ID on the page, with the ID as the suffix, for example _ga_ABC123XYZ. It persists session state for that property, including the current session ID and how many sessions the browser has had, so GA4 can group hits into sessions.

Seeing two or more _ga_ cookies on one site usually means more than one GA4 property is loaded. Google documents the name as _ga_<container-id> and a 2 year default lifetime, configurable through the same GA4 cookie settings as _ga.

What TagPipes observed

49%

of sites scanned set it (20,302 of 41,162)

400 days

median observed lifetime

TagPipes scanned 41,162 public websites between August 11, 2026 and September 13, 2026, loading up to three pages per site in a real browser as a first-time visitor. _ga_<container-id> was present on 20,302 of them.

It was set as a first-party cookie on 19,967 sites and as a third-party cookie on 503. A site can count in both. Where it was stored as a persistent cookie, the median lifetime we recorded was 400 days, and it was a session cookie on 8 sites. Chrome limits any cookie to 400 days, so a longer lifetime set by the vendor shows up as about 13 months in Chrome.

Often found alongside

Percentage of sites with _ga_<container-id> where the other cookie was also present.

Technologies detected on the same sites

Google Analytics on 100% of them (55% of all sites scanned)
Google Fonts on 89% of them (78% of all sites scanned)
Google Tag Manager on 55% of them (30% of all sites scanned)
reCAPTCHA on 26% of them (32% of all sites scanned)
DoubleClick on 20% of them (11% of all sites scanned)

Aggregate figures across all sites scanned. Websites of TagPipes customers are excluded, no individual site is named, and cookie values are never read or stored. Snapshot dated September 13, 2026.

How to check for _ga_<container-id> on a website

Open the site in Chrome, then open DevTools (F12, or Cmd+Option+I on a Mac).
Go to the Application tab and expand Cookies in the left panel.
Select each domain listed there and look for a name starting with _ga_. The Expires column shows when it will be deleted.
If it is not there, reload the page. Many cookies are only set after a tag has loaded, and some only after a visitor has made a consent choice.

Sources

Purpose, duration and value format checked against the vendor documentation above on September 26, 2026. The figures under What TagPipes observed are TagPipes scan data from September 13, 2026, not values documented by the vendor. Vendors change their cookies, and sites can configure their own names and lifetimes. Browse all cookies.

Know every cookie your own site sets

TagPipes Pulse identifies the cookies dropped on your site and flags unclassified or miscategorized ones. Shield builds your cookie declaration from a real scan rather than a questionnaire.

See Pulse See Shield

TagPipes monitors, configures and reports. It does not determine legal compliance and does not provide legal advice. Output is informational and reflects observed state at the time of observation. Rawsoft's expertise is technology, not law; please confirm any regulatory interpretation with your own counsel.