# Visitor id not same in browser vs tracker debugger

**URL:** <https://community.piwik.pro/t/visitor-id-not-same-in-browser-vs-tracker-debugger/2782>\
**Category:** Data collection and tags\
**Created:** [August 27, 2023, 9:54am UTC](https://community.piwik.pro/t/visitor-id-not-same-in-browser-vs-tracker-debugger/2782 "2023-08-27T09:54:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dandan](https://avatars.discourse-cdn.com/v4/letter/d/a87d85/32.png) [@dandan](https://community.piwik.pro/u/dandan)\
**Post date:** [August 27, 2023, 9:54am UTC](https://community.piwik.pro/t/visitor-id-not-same-in-browser-vs-tracker-debugger/2782/1 "2023-08-27T09:54:21Z")

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Hi,

I just want to wrap my head around the working. Visiting my website on icognito I see a certain visitor id using dev tools. Both in the calls and in the cookies saved by piwik. But these does not exist in the Tracker debugger. I manage to find my visit (I visit the website via a unique utm so I know it’s my visit) and then there is a visitor id that is completely diffrent from the one seeing in dev tools. How does this work? Does Piwik use fingerprinting somehow in these cases? so despite there not being a cookie in my device it still attributes it to my intitall visitor ID i had first time I visited? Anyone knows how this work or can point me to the correct article?

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**Author:** ![sararekowska](https://dub1.discourse-cdn.com/flex005/user_avatar/community.piwik.pro/sararekowska/32/1582_2.png) [@sararekowska](https://community.piwik.pro/u/sararekowska)\
**Post date:** [August 28, 2023, 10:29am UTC](https://community.piwik.pro/t/visitor-id-not-same-in-browser-vs-tracker-debugger/2782/2 "2023-08-28T10:29:56Z")

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Hi there!

The ID visible in debug tools is the Cookie ID - the value saved in the \_pk\_id cookie, while the Visitor ID in our product is the actual Visitor ID, which can be calculated based on the Cookie ID and/or Session ID.

It can be different, because the actual Visitor ID also takes the Session ID into account.  
The problem is - Cookie ID may still be called ‘Visitor ID’ in some places in our JavaScript Tracking Client. We are aware of that and we’re planning to simplify all of this a lot.

Here’s an article that goes into more detail on how Session ID works: [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/#session-id) 😄