DocumentationAnalyticsImplementation Guide

visitorID

Last update: Thu Feb 19 2026 00:00:00 GMT+0000 (Coordinated Universal Time)

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Adobe uses several different methods to identify visitors on your site. The visitorID variable overrides all other methods of visitor identification.

IMPORTANT
Adobe advises against using this variable. Use the Adobe Experience Cloud Identity Service instead.

How Analytics uses visitorID

This variable is a manual visitor ID override that replaces all other forms of visitor identification. To be counted as a single visitor, every hit for a person must use the same visitorID value.

  • Hits that omit visitorID fall back to another visitor identification method and are treated as a separate visitor.
  • Hits that use more than one visitorID value are treated as separate visitors.
  • Adobe does not stitch hits that use different visitor IDs together.

See Visitor identification in Adobe Analytics for details on identification precedence and why mixing identifiers can inflate visitor counts.

WARNING
Set visitorID only if you can guarantee that it is set on every hit for that person and that the value never changes. Setting it on only some hits, introducing it partway through a visit (such as on authentication), or changing it between hits splits a single visitor’s activity into multiple visitors.
CAUTION
Invalid custom visitor ID values can lead to incorrect data and poor reporting performance. If this variable contains a default or placeholder value (such as "0" or "NULL"), Adobe treats these hits as if they are the same visitor. This situation results in incorrect data, with artificially low visitor counts and visitor-level segments not working as expected. Incorrectly implemented custom visitor IDs can also introduce heavy load on processing servers, increasing latency and decreasing report performance.

Visitor ID using the Adobe Analytics extension

Visitor ID is a field under the Cookies accordion when configuring the Adobe Analytics extension.

  1. Log in to Adobe Experience Platform Data Collection using your AdobeID credentials.
  2. Select the desired tag property.
  3. Go to the Extensions tab, then select the Configure button under Adobe Analytics.
  4. Expand the Cookies accordion, which reveals the Visitor ID field.

Assign this field to the data element containing your custom visitor ID. Do not set this field to a single static value for all visitors. Use a data element that resolves per visitor and remains constant across all hits.

s.visitorID in AppMeasurement and the Analytics extension custom code editor

The s.visitorID variable is a string that contains a custom unique identifier for the visitor. Valid values include alphanumeric characters up to 100 bytes. Avoid using dashes, spaces, underscores, or symbols in this variable.

s.visitorID = "abc123";

Visitor ID using the Web SDK

The Adobe Experience Platform Edge Network allows you to provide multiple identifiers using XDM’s Identity Map. Each identity in an Identity Map has a different namespace. You can specify which namespace should be used for visitor ID as part of datastream configuration. Once this field is configured, when you send an event with a value specified for this namespace, it is automatically used as the visitor ID in Analytics.

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