explaingit

reactjs/react-transition-group

★ 10,247JavaScriptAudience · developerComplexity · 2/5Setup · easy

TLDR

React Transition Group is a React library that lets you apply CSS animations when components appear or disappear from the screen by exposing entering, active, and leaving states you can style however you want.

Mindmap

mindmap
  root((repo))
    What it does
      Transition states
      CSS class management
      Mount and unmount hooks
      Timing control
    Tech Stack
      JavaScript React
      TypeScript types
      CSS animations
    Use Cases
      Fade animations
      Page transitions
      List animations
    Audience
      React developers
      Frontend engineers
Click or tap to explore — scroll the page freely

Code map

Detail Auto

An interactive map of this repo's files and how they connect — its source is parsed live in your browser. Click Visualize to build it.

filefunction / class

Things people build with this

USE CASE 1

Add fade-in and fade-out CSS animations when React components mount and unmount

USE CASE 2

Create animated page transitions by attaching entering and leaving states to route components

USE CASE 3

Animate list items as they are added to or removed from a list using TransitionGroup

USE CASE 4

Control the timing and CSS classes of any component animation without a heavy animation library

Tech stack

JavaScriptTypeScriptReactCSS

Getting it running

Difficulty · easy Time to first run · 30min

In plain English

React Transition Group is a JavaScript library for React that helps you add animations when components appear on screen, disappear from screen, or transition between states. The core idea is that when you show or hide something in a React app, you often want a visual effect rather than an abrupt pop-in or pop-out. This library gives you the building blocks to control what happens at those moments. It works by tracking whether a component is entering, active, or leaving the page, and exposing that state so you can attach CSS classes or inline styles at each stage. The typical pattern is: apply one set of styles when something appears, hold at a second set of styles while it is visible, and apply a third set when it is removed. The library handles the timing and cleanup rather than leaving that up to you. The package is maintained under the official React community GitHub organization and is available as an npm package. TypeScript type definitions are published separately through the DefinitelyTyped project. The README is brief and points to external documentation for full usage details. There is a version 1 of the library that was a direct replacement for older React add-ons, but it is no longer updated. The current version 2 and above has a different API and is not backwards compatible with version 1. The README includes a migration guide for anyone moving between the two.

Copy-paste prompts

Prompt 1
Using React Transition Group, write a React component that fades in smoothly when it mounts and fades out when it unmounts using CSS classes.
Prompt 2
How do I use React Transition Group to animate a dropdown menu sliding down when it opens and sliding back up when it closes?
Prompt 3
Show me how to use the TransitionGroup component to animate items being added and removed from a list so each one fades in or out individually.
Prompt 4
I'm migrating a project from React Transition Group v1 to v2. What are the main API differences I need to update in my components?
Open on GitHub → Explain another repo

← reactjs on gitmyhub — every repo by this author, as a profile.

Verify against the repo before relying on details.