Analytics Cookies | Documentation

Overview

Client-side cookies (JS SDK)

NAME	TYPE & CATEGORY	LIFETIME	OBJECT	PURPOSE	USER OPT-OUT EFFECT	PROCESSING PARTY
`pa_user`	Cookie (Optional)	13 months by default, can be configured	Stored user information	The `pa_user` cookie tracks an authenticated visitor (user) over time, even if the user does not log in again during subsequent visits. This cookie is managed by the customer who chooses its value and decides if the cookie should be set or not	No persistence of user information information in events	2

Piano Analytics uses other client-side cookies for visitor detection, Privacy management and cross-product context sharing. See the Cross-Product Cookies section as these cookies are used by other Piano products as well.

Server-side cookies

The visitor detection can be managed with server-side cookies if needed (to bypass browsers' limitations or benefit from cross-site visitor tracking).

In this case, we deposit three cookies with different technical attributes for the same visitor identification goal and the same ID. This ensures that at least one cookie is deposited depending on the browser.

NAME	TYPE & CATEGORY	LIFETIME	OBJECT	PURPOSE	USER OPT-OUT EFFECT	PROCESSING PARTY
`idrxvr`	Cookie (Essential)	13 months	Legacy server-side visitor ID	Used instead of `_pcid` to perform visitor detection.	New cookie set, new visitor ID assigned	2
`atidx`	Cookie (Essential)	13 months	Server-side visitor ID	Used instead of `_pcid` to perform visitor detection. Contains a "secure flag".	New cookie set, new visitor ID assigned	2
`atid`	Cookie (Essential)	13 months	Main Server-side visitor ID	Used instead of `_pcid` to perform visitor detection. Contains a "secure flag" and "SameSite=none" attribute.	New cookie set, new visitor ID assigned	2

*1 = first-party cookies (managed by publishers), 2 = first-party cookies (managed and set by Piano), 3 = third-party cookies.

Piano Analytics Mobile SDKs

Android & Apple

STORAGE KEY	LIFETIME	OBJECT
`pa_vid`	13 months by default, can be configured	Visitor ID
`pa_uid`	13 months by default, can be configured	Stored user information
`pa_privacy`	13 months by default, can be configured	Privacy Mode persistence
`pa_crash`	Until app relaunch	Crash information
`pa_lifecycle`	No expiration	Application lifecycle

More details about Cookies & Storage in Piano Analytics are available in this documentation.

Last updated: June 23, 2026