> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upstackdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Logins: Track Customer Authentication Events

> Track login events on your site. Measure customer authentication frequency to understand returning visitor engagement and account usage.

<Tip>
  Logins measures the total number of times visitors authenticated (logged in) to their accounts on your site.
</Tip>

## Formula

<Info>
  **Logins** = **COUNT** ( Login Events )
</Info>

### Formula Components

| Metric           | Definition                                                                   |
| ---------------- | ---------------------------------------------------------------------------- |
| **Login Events** | Individual authentication events tracked when a user logs into their account |

| Metadata        |                         |
| --------------- | ----------------------- |
| **Type**        | Number                  |
| **Data Source** | [Upstack Pixel](/pixel) |
| **Aggregation** | Count                   |

***

## Example

Your store recorded **4,823 logins** in March, indicating strong account engagement from returning customers.

| Week   | Logins | Change |
| ------ | ------ | ------ |
| Week 1 | 1,156  | —      |
| Week 2 | 1,203  | +4.1%  |
| Week 3 | 1,187  | -1.3%  |
| Week 4 | 1,277  | +7.6%  |

***

## How It Works

The Upstack pixel fires a login event each time a visitor successfully authenticates on your site. This includes logins from the main site, checkout, and any other authentication touchpoints. Each successful authentication counts as one login event, regardless of session or device.

***

## When to Use

| Scenario                         | Action                                                                           |
| -------------------------------- | -------------------------------------------------------------------------------- |
| Measure account engagement       | Track login frequency to understand how often customers return to their accounts |
| Identify authentication friction | Compare logins to account creation to spot drop-off in returning users           |
| Segment returning customers      | Use login data to identify your most engaged account holders                     |
| Evaluate loyalty programs        | Monitor login trends after launching member-only benefits or rewards             |

***

## Related Metrics

| Metric                                                           | Relationship                                                         |
| ---------------------------------------------------------------- | -------------------------------------------------------------------- |
| [Sessions](/reference/metrics/funnel/awareness/sessions)         | Total site visits — logins represent authenticated sessions          |
| [Page Views](/reference/metrics/funnel/awareness/page-views)     | Overall engagement — logins indicate deeper account-level engagement |
| [Conversions](/reference/metrics/funnel/conversions/conversions) | Purchase completions — logged-in users often convert at higher rates |

[See all Engagement metrics →](/reference/metrics/funnel/engagement)