The getEntriesByName() method returns a list of PerformanceEntry objects for the given name and type. The list's members (entries) can be created by making performance marks or measures (for example by calling the mark() method) at explicit points in time.
The getEntriesByType() method returns a list of PerformanceEntry objects for a given type. The list's members (entries) can be created by making performance marks or measures (for example by calling the mark() method) at explicit points in time.
The measure() method creates a named timestamp in the browser's performance entry buffer between two specified marks (known as the start mark and end mark, respectively). The named timestamp is referred to as a measure.
The PerformanceEntry object encapsulates a single performance metric that is part of the performance timeline. A performance entry can be directly created by making a performance mark or measure (for example by calling the mark() method) at an explicit point in an application. Performance entries are also created in indirect ways such as loading a resource (such as an image).
The PerformanceFrameTiming interface provides frame timing data about the browser's event loop. A frame represents the amount of work a browser does in one event loop such as processing DOM events, resizing, scrolling, rendering, CSS animations, etc. A frame rate of 60fps (frames per second) for a 60Hz refresh rate is the target for a good responsive user experience. This means the browser should process a frame in about 16.7ms.
The PerformanceNavigationTiming interface provides methods and properties to store and retrieve high resolution timestamps or metrics regarding the browser's document navigation events. For example, this interface can be used to determine how much time it takes to load or unload a document.
The domInteractive property returns a timestamp representing the time value equal to the time immediately before the user agent sets the current document readiness of the current document to interactive.