W3C Performance Specifications

Here are some of the W3C’s web performance specifications:

• High Resolution Time (Level 3)

  The DOMHighResTimeStamp type, performance.now method, and performance.timeOrigin attributes of the Performance interface resolve Date.now() issues with monotonically increasing time values with sub-millisecond resolution.

  https://w3c.github.io/hr-time

• Performance Timeline (Level 2)

  Extends definition of the Performance interface, exposes PerformanceEntry in Web Workers and adds support for the PerformanceObserver interface.

  https://w3c.github.io/performance-timeline

• Resource Timing (Level 3)

  Defines the PerformanceResourceTiming interface providing timing information related to resources in a document.

  https://w3c.github.io/resource-timing https://w3c.github.io/navigation-timing
  Supported in all browser except Safari and Opera Mini, starting with IE10

• User Timing (Level 2)

  Extends Performance interface with PerformanceMark and PerformanceMeasure.

  https://w3c.github.io/user-timing
  Supported in all browser except Safari and Opera Mini, starting with IE10

• Beacon API

  Defines a beacon API which can “guarantee” asynchronous and non-blocking delivery of data, while minimizing resource contention with other time-critical operations.

  https://w3c.github.io/beacon
  Not supported in IE, Safari or Opera Mini. Support started with Edge 14
  navigator.sendBeacon() on MDN

• Preload

  Defines preload for resources which need to be fetched as early as possible, without being immediately processed and executed. Preloaded resources can be specified via declarative markup, the Link HTTP header, or scheduled with JS.

  https://w3c.github.io/preload

• Cooperative Scheduling of Background Tasks

  Adds the requestIdleCallback method on the Window object, which enables the browser to schedule a callback when it would otherwise be idle, along with the associated cancelIdleCallback and timeRemaining methods.

  https://w3c.github.io/requestidlecallback