What the gtm_session_start cookie does
Measures how long an activity takes and collects information about user website usage.
Who sets it
Consent category: analytics
Analytics cookies measure how a site is used, in aggregate: pages seen, sessions, where visitors came from. Under the GDPR they need consent before they are set, and Google Consent Mode can model what is lost when visitors decline.
| Name | gtm_session_start |
|---|---|
| Category | Analytics |
| Set by | Google Tag Manager |
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From the Conzent cookie database, last updated 2026-09-27. Descriptions come from vendor documentation, cookie policies and our own scans; write to support@getconzent.com to correct one.