requestAnimationFrame

Rendering

A method that tells the browser you wish to perform an animation and requests that the browser calls a specified function to update an animation before the next repaint.

Beginner⚡ 95% usage

IntersectionObserver

Observers

An API that provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document viewport.

Intermediate⚡ 85% usage

MutationObserver

Observers

Provides the ability to watch for changes being made to the DOM tree.

Intermediate⚡ 85% usage

Web Workers

Concurrency

An API that enables executing JavaScript in background threads. The worker thread can perform tasks without interfering with the user interface.

Advanced⚡ 75% usage

ResizeObserver

Observers

An API that lets you efficiently observe changes to the size of elements, replacing the unreliable window.resize event for element-level layout tracking.

Beginner⚡ 70% usage

requestIdleCallback

Concurrency

An API that schedules low-priority work to run during browser idle periods, keeping the main thread available for user interactions and animations while still completing background tasks.

Intermediate⚡ 60% usage

PerformanceObserver

Observers

An interface to observe performance measurement events and receive notifications of new performance entries (like LCP, CLS, or Long Tasks).

Advanced⚡ 60% usage

View Transitions API

Rendering

Enables smooth, app-like visual transitions between different states of the DOM, including between entirely different documents (Multi-Page Apps).

Intermediate⚡ 45% usage