--- title: Analyze Performance with Metrics description: >- Understand the out-of-the-box performance metrics that are available with RUM without Limits. breadcrumbs: >- Docs > RUM & Session Replay > RUM without Limits > Analyze Performance with Metrics --- # Analyze Performance with Metrics ## Overview{% #overview %} {% image source="https://docs.dd-static.net/images/real_user_monitoring/rum_without_limits/filters-rum-measure-view.1a5f6eeec721063776db644416d77fc4.png?auto=format&fit=max&w=850 1x, https://docs.dd-static.net/images/real_user_monitoring/rum_without_limits/filters-rum-measure-view.1a5f6eeec721063776db644416d77fc4.png?auto=format&fit=max&w=850&dpr=2 2x" alt="Visualization of Android app crash-free sessions percentage over four weeks." /%} Datadog provides the below out-of-the-box metrics for a comprehensive overview of your application's health over time. To ensure accuracy, these metrics are computed prior to retaining or discarding any sessions. This means that even though you keep 0.01% of your sessions, these metrics are computed based on 100% of the ingested sessions. These metrics are powering the [performance summary](https://app.datadoghq.com/rum/performance-monitoring) to give you an accurate overview of the performance of your apps. **Notes**: - The **Default** cardinality set in the table below includes the following dimensions: environment, app name, app ID, app version, service, OS name, OS version, browser name, and country. - All queries for the below metrics include `@session.type:user`. - If you need performance metrics beyond the ones listed below, you can create [custom metrics](https://docs.datadoghq.com/real_user_monitoring/platform/generate_metrics.md) from your RUM events. Both OOTB and custom metrics are computed based on 100% of the traffic ingested. - Some metrics are captured when a session or view is first detected. Others are captured when it becomes inactive. Comparing these metrics over short time windows can produce unexpected ratios. See When metrics are computed. | Metric Name | Description | Dimensions | Platform | | -------------------------------------------- | ----------------------------------------------------------------------------------------------------------- | ----------------------------------------- | ---------------- | | `rum.measure.app.startup_time` | App startup time | Default, Percentiles breakdown | Mobile only | | `rum.measure.error` | Count of errors | Default, Is Crash, View Name | Mobile & Browser | | `rum.measure.error.anr` | Count of ANRs (an Android freeze) | Default, Is Crash, View Name | Mobile only | | `rum.measure.error.hang` | Count of hangs (an iOS freeze) | Default | Mobile only | | `rum.measure.error.hang.duration` | Duration of hangs (an iOS freeze) | Default, View Name | Mobile only | | `rum.measure.session` | Count of sessions | Default | Mobile & Browser | | `rum.measure.session.action` | Count of actions | Default | Mobile & Browser | | `rum.measure.session.crash_free` | Count of crash-free sessions | Default | Mobile only | | `rum.measure.session.error` | Count of errors per session (@session.error.count) | Default, Percentiles breakdown | Mobile & Browser | | `rum.measure.session.frustration` | Count of frustration signals | Default | Mobile & Browser | | `rum.measure.session.inactive` | Count of inactive sessions | Default | Mobile & Browser | | `rum.measure.session.time_spent` | Session duration | Default, Percentiles breakdown | Mobile & Browser | | `rum.measure.view` | Count of views | Default, View Name | Mobile & Browser | | `rum.measure.view.cpu_ticks_per_second` | CPU ticks per second | Default, View Name | Mobile only | | `rum.measure.view.crash_free` | Crash-free session rate | Default, View Name | Mobile only | | `rum.measure.view.cumulative_layout_shift` | Cumulative Layout Shift | Default, Percentiles breakdown, View Name | Browser only | | `rum.measure.view.loading_time` | Time until the page is ready and no network request or DOM mutation is currently occurring. | Default, Percentiles breakdown, View Name | Mobile & Browser | | `rum.measure.view.error_free` | Count of error free sessions | Default, View Name | Mobile & Browser | | `rum.measure.view.first_contentful_paint` | Time when the browser first renders any text, image (including background images), non-white canvas, or SVG | Default, Percentiles breakdown, View Name | Browser only | | `rum.measure.view.frozen_frame` | Count of frozen frames | Default, View Name | Mobile only | | `rum.measure.view.frozen_frame_free` | Count of views without frozen frames | Default | Mobile only | | `rum.measure.view.inactive` | Count of inactive views | Default, Percentiles breakdown | Mobile & Browser | | `rum.measure.view.interaction_to_next_paint` | Longest duration between a user's interaction with the page and the next paint. | Default, Percentiles breakdown | Browser only | | `rum.measure.view.interaction_to_next_view` | Time between the last user interaction in the previous view and the start of the current view | Default, Percentiles breakdown | Mobile only | | `rum.measure.view.largest_contentful_paint` | Time in the page load where the largest DOM object in the viewport (visible on screen) is rendered | Default, Percentiles breakdown, View Name | Browser only | | `rum.measure.view.memory` | Amount of system memory used | Default, Percentiles breakdown | Mobile only | | `rum.measure.view.network_settled` | Network settled | Default, Percentiles breakdown | Mobile only | | `rum.measure.view.refresh_rate` | Average of user's refresh rate (FPS) | Default, Percentiles breakdown | Mobile only | | `rum.measure.view.slow_rendered` | Count of slow rendered views | Default | Mobile only | | `rum.measure.view.time_spent` | Time spent on the current view | Default | Mobile & Browser | ## When metrics are computed{% #when-metrics-are-computed %} Metrics are captured at different points in a session or view life cycle: - **On detection**: `rum.measure.session` and `rum.measure.view` are captured when a session or view is first detected. - **On inactivity**: Metrics such as `rum.measure.session.inactive`, `rum.measure.session.crash_free`, `rum.measure.view.inactive`, and `rum.measure.view.crash_free` are captured when a session or view becomes inactive (that is, when the session or view ends). Because a session or view that starts in one time window can end in a different time window, comparing on-detection metrics with on-inactivity metrics over short time windows can produce unexpected results, including ratio values above 100%. For example, if many sessions from the previous day are still active and end during the current day, the number of inactive sessions counted today can exceed the number of sessions that started today. This means a ratio like crash-free session rate (`rum.measure.session.crash_free` / `rum.measure.session`) can legitimately return a value above 100%—this is expected behavior. **Recommendation**: When computing ratios that combine on-detection and on-inactivity metrics, use a time window large enough to capture both the start and end of most sessions (for example, one week or more). ## API{% #api %} Metrics can be managed through [APIs](https://docs.datadoghq.com/api/latest/rum-metrics.md) or Datadog's dedicated [Terraform modules](https://registry.terraform.io/providers/DataDog/datadog/3.60.0/docs/resources/rum_metric). ## Further reading{% #further-reading %} - [RUM without Limits](https://docs.datadoghq.com/real_user_monitoring/rum_without_limits.md) - [Retention Filters](https://docs.datadoghq.com/real_user_monitoring/rum_without_limits/retention_filters.md) - [Control Costs with Retention Quotas](https://docs.datadoghq.com/real_user_monitoring/rum_without_limits/retention_quotas.md) - [Retention Filter Best Practices](https://docs.datadoghq.com/real_user_monitoring/guide/retention_filter_best_practices.md)