# How the data is collected in anonymous mode?

**URL:** <https://community.piwik.pro/t/how-the-data-is-collected-in-anonymous-mode/1563>\
**Category:** Data collection and tags\
**Created:** [January 30, 2023, 2:15pm UTC](https://community.piwik.pro/t/how-the-data-is-collected-in-anonymous-mode/1563 "2023-01-30T14:15:26Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![lisa](https://avatars.discourse-cdn.com/v4/letter/l/f08c70/32.png) [@lisa](https://community.piwik.pro/u/lisa)\
**Post date:** [January 30, 2023, 2:15pm UTC](https://community.piwik.pro/t/how-the-data-is-collected-in-anonymous-mode/1563/1 "2023-01-30T14:15:26Z")

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Hi !

In our website we use the API to anonymize users. We wanted to understand how an anonymous visitor is recognized between pages as there are no session ID/visitor ID stored ?

Thanks,  
Lisa

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**Author:** ![Admin](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Admin](https://community.piwik.pro/u/Admin)\
**Post date:** [January 30, 2023, 2:17pm UTC](https://community.piwik.pro/t/how-the-data-is-collected-in-anonymous-mode/1563/2 "2023-01-30T14:17:33Z")

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Hi. What is your current configuration? When you disable session ID / Cookie ID / User ID, each event should create a new session.

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**Author:** ![lisa](https://avatars.discourse-cdn.com/v4/letter/l/f08c70/32.png) [@lisa](https://community.piwik.pro/u/lisa)\
**Post date:** [January 30, 2023, 5:08pm UTC](https://community.piwik.pro/t/how-the-data-is-collected-in-anonymous-mode/1563/3 "2023-01-30T17:08:14Z")

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Hi Kuba,  
We didn’t desabled session ID / cookie ID but in my storage I didn’t see any ID when I am an anonymous user

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<div class="post-metadata">

**Author:** ![Admin](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Admin](https://community.piwik.pro/u/Admin)\
**Post date:** [January 30, 2023, 6:01pm UTC](https://community.piwik.pro/t/how-the-data-is-collected-in-anonymous-mode/1563/4 "2023-01-30T18:01:00Z")

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Session ID (the one Piwik PRO uses to stitch events into sessions) is done on the backend side. So that’s normal that you don’t see it.

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**Author:** ![lisa](https://avatars.discourse-cdn.com/v4/letter/l/f08c70/32.png) [@lisa](https://community.piwik.pro/u/lisa)\
**Post date:** [January 31, 2023, 8:09am UTC](https://community.piwik.pro/t/how-the-data-is-collected-in-anonymous-mode/1563/5 "2023-01-31T08:09:22Z")

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Thanks ! And how the session ID is attributed to the same session ? How do you know that is the same session ?

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**Author:** ![Admin](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Admin](https://community.piwik.pro/u/Admin)\
**Post date:** [January 31, 2023, 8:23am UTC](https://community.piwik.pro/t/how-the-data-is-collected-in-anonymous-mode/1563/6 "2023-01-31T08:23:23Z")

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Please check this article: [What is a session and how is it counted? | Piwik PRO help center](https://help.piwik.pro/support/questions/how-is-a-session-counted-in-piwik-pro/)