amplitude_id_ cookie: what it does, who sets it, consent category

amplitude_id_ cookie

Analytics cookie set by Amplitude, lasting Session.

Is amplitude_id_ firing on your site before anyone says yes?

Conzent holds amplitude_id_ and every other analytics cookie until the visitor accepts, and Consent Mode v2 keeps your Google Ads and GA4 reporting accurate. Registered IAB TCF CMP, Google-certified. From €7 per site a month.

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What the amplitude_id_ cookie does

In previous versions of the Amplitude JavaScript SDK, the cookie key was set by default to amplitude_id; this may appear in projects that use an SDK version prior to 6.0.0. In that case, the cookie is set under the key

The name ends in a part that changes from visitor to visitor or site to site, so this entry covers every cookie whose name starts with amplitude_id_.

Who sets it

Amplitude — privacy policy

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	`amplitude_id_`
Category	Analytics
Lifetime	Session
Set by	Amplitude

Other cookies from the same vendor

Is this cookie on your site?

Conzent's scanner lists every cookie your site sets, classifies each one the way this page does, and shows which are set before the visitor has consented. Try Conzent free for 14 days, or look up another cookie.

From the Conzent cookie database, last updated 2026-10-11. Descriptions come from vendor documentation, cookie policies and our own scans; write to support@getconzent.com to correct one.