--- title: "End device Visitor Ids" slug: "end-device-visitor-ids" updated: 2024-08-27T14:49:16Z published: 2024-08-27T14:49:16Z canonical: "docs.mapp.com/end-device-visitor-ids" --- > ## Documentation Index > Fetch the complete documentation index at: https://docs.mapp.com/llms.txt > Use this file to discover all available pages before exploring further. # End device Visitor Ids **Shows a unique visitor ID, that is written into a cookie created by Mapp. This cookie ID is unique for each Mapp Intelligence account and (when using 1st party cookies) for each domain.** > In order to identify a user as unique as possible, use the dimension "Visitor Id". Here also login information (customer ID; if available) is taken into account for the visitor identification. #### Syntax of the ID End device Visitor Id is composed by several information: - **Cookies created by the server (3rd party cookies)** Syntax: 4 + timestamp (10-digit) + 8-digit random number - **Cookies created by the browser (1st party cookies)** Syntax: 2 + timestamp (10-digit) + 8-digit random number - **invalid EID (contains letters, is too long or too short)** Syntax: 5 + timestamp (10-digit) + 8-digit random number - **When using SDKs** Syntax: 6 + timestamp (10-digit) + 8-digit random number #### Name of the cookies The cookies are called "wt3_eid" when using 1st party cookies. When using 3rd party cookies they are called "wteid_<>". The visitor ID is submitted to Mapp in the parameter "eid" when using 1st party cookies. #### Duration The duration of the cookie is 6 months by default and can be changed in Mapp Tag Integration (when using 1st party cookies) or by the Mapp consulting (when using 3rd party cookies). A new ID is generated at the next visit in case the cookie was deleted manually or after 6 months of inactivity. ## Additional Information [User Centric Tracking (1): An introduction](/v1/docs/user-centric-tracking-1-an-introduction) ## Related - [Custom Visitor Id](/custom-visitor-id.md) - [Visitor Id](/visitor-id.md)