Limited Availability
11 featuresThe notRestoredReasons property of a PerformanceNavigationTiming object explains why the current document was blocked from using the back/forward cache (also known as the bfcache) on navigation.
A container performance entry measures time to render child elements, for container elements that have the containertiming attribute.
The element performance entry and the PerformanceElementTiming API measures the time to render elements that have the elementtiming attribute.
The interaction-contentful-paint performance entry, which returns an InteractionContentfulPaint instance, is emitted when an interaction causes one or more contentful paints. Use it to measure LCP for soft navigations in single page apps or to measure contentful paints due to an interaction.
The layout-shift performance entry and LayoutShift API measures the layout stability of web pages based on movements of the elements on the page. They're used to calculate Cumulative Layout Shift (CLS), a common metric for perceived stability.
The long-animation-frame performance event type and the PerformanceLongAnimationFrameTiming API provide information about rendering updates that take longer than 50 milliseconds. Also known as LoAFs.
The longtask performance event type and the PerformanceLongTaskTiming API provides information about tasks that occupy the UI thread for 50 milliseconds or more, a metric for input latency, delayed animations, and other sources of "jank."
The measureUserAgentSpecificMemory() method estimates the memory usage of a web application including all its iframes and workers.
The visibility-state performance entry and the VisibilityStateEntry API measure the timing of page visibility state changes, such as when a tab is no longer visible or the user has switched to another app.
The window.performance.timing and window.performance.navigation APIs report performance timing information for events that occur during the loading and use of the current page.