> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/feature-flags/use-feature-flags/use-ff/ff-data/anonymous-users-maus.md).

# Track Anonymous Users & Monthly Active Users

This topic defines anonymous users, how their data is handled in Harness Feature Flags, and how they relate to the Monthly Active Users (MAUs) count.

This topic defines anonymous users, how their data is handled in Harness Feature Flags, and how they relate to the Monthly Active Users (MAUs) count.

{% hint style="info" %}
**NOTE**

Monthly Active Users (MAUs) are only applicable to client-side applications (JavaScript, iOS, Android, React, etc.).
{% endhint %}

### How do anonymous users contribute to MAUs? <a href="#how-do-anonymous-users-contribute-to-maus" id="how-do-anonymous-users-contribute-to-maus"></a>

MAUs are defined as unique end users evaluating flags from client-side SDKs (JavaScript, iOS, Android, React, etc.) over a 30-day period. If a user evaluates flags across multiple devices and sessions in a 30-day period, we count this as 1 MAU.

* Anonymous users can be assigned a target ID as any other target would, ensuring that multiple visits only account for one MAU. Essentially, you'd create a single target that applies to all of your anonymous traffic, and the anonymous traffic would be counted as one MAU.

{% @harness-feedback/feedback %}