Full list of changes: * refactor: data source for errors and warnings tracking is now in Store ([hoxyq](https://github.com/hoxyq) in [#31010](https://github.com/facebook/react/pull/31010)) * fix: consider alternate as a key for componentLogsEntry when inspecting raw fiber instance ([hoxyq](https://github.com/hoxyq) in [#31009](https://github.com/facebook/react/pull/31009)) * Fix: profiling crashes #30661 #28838 ([EdmondChuiHW](https://github.com/EdmondChuiHW) in [#31024](https://github.com/facebook/react/pull/31024)) * chore: remove using local storage for persisting console settings on the frontend ([hoxyq](https://github.com/hoxyq) in [#31002](https://github.com/facebook/react/pull/31002)) * feat: display message if user ended up opening hook script ([hoxyq](https://github.com/hoxyq) in [#31000](https://github.com/facebook/react/pull/31000)) * feat: expose installHook with settings argument from react-devtools-core/backend ([hoxyq](https://github.com/hoxyq) in [#30987](https://github.com/facebook/react/pull/30987)) * chore: remove settings manager from react-devtools-core ([hoxyq](https://github.com/hoxyq) in [#30986](https://github.com/facebook/react/pull/30986)) * feat[react-devtools/extension]: use chrome.storage to persist settings across sessions ([hoxyq](https://github.com/hoxyq) in [#30636](https://github.com/facebook/react/pull/30636)) * refactor[react-devtools]: propagate settings from global hook object to frontend ([hoxyq](https://github.com/hoxyq) in [#30610](https://github.com/facebook/react/pull/30610)) * chore[react-devtools]: extract some utils into separate modules to unify implementations ([hoxyq](https://github.com/hoxyq) in [#30597](https://github.com/facebook/react/pull/30597)) * refactor[react-devtools]: move console patching to global hook ([hoxyq](https://github.com/hoxyq) in [#30596](https://github.com/facebook/react/pull/30596)) * refactor[react-devtools]: remove browserTheme from ConsolePatchSettings ([hoxyq](https://github.com/hoxyq) in [#30566](https://github.com/facebook/react/pull/30566)) * feat[react-devtools]: add settings to global hook object ([hoxyq](https://github.com/hoxyq) in [#30564](https://github.com/facebook/react/pull/30564)) * fix: add Error prefix to Error objects names ([hoxyq](https://github.com/hoxyq) in [#30969](https://github.com/facebook/react/pull/30969)) * Add enableComponentPerformanceTrack Flag ([sebmarkbage](https://github.com/sebmarkbage) in [#30960](https://github.com/facebook/react/pull/30960)) * fix[rdt/fiber/renderer.js]: getCurrentFiber can be injected as null ([hoxyq](https://github.com/hoxyq) in [#30968](https://github.com/facebook/react/pull/30968)) * disable `enableSiblingPrerendering` in experimental channel ([gnoff](https://github.com/gnoff) in [#30952](https://github.com/facebook/react/pull/30952)) * refactor[react-devtools]: initialize renderer interface early ([hoxyq](https://github.com/hoxyq) in [#30946](https://github.com/facebook/react/pull/30946)) * Start prerendering Suspense retries immediately ([acdlite](https://github.com/acdlite) in [#30934](https://github.com/facebook/react/pull/30934)) * refactor[Agent/Store]: Store to send messages only after Agent is initialized ([hoxyq](https://github.com/hoxyq) in [#30945](https://github.com/facebook/react/pull/30945)) * refactor[RendererInterface]: expose onErrorOrWarning and getComponentStack ([hoxyq](https://github.com/hoxyq) in [#30931](https://github.com/facebook/react/pull/30931)) * Implement getComponentStack and onErrorOrWarning for replayed Flight logs ([sebmarkbage](https://github.com/sebmarkbage) in [#30930](https://github.com/facebook/react/pull/30930)) * Use Unicode Atom Symbol instead of Atom Emoji ([sebmarkbage](https://github.com/sebmarkbage) in [#30832](https://github.com/facebook/react/pull/30832)) * Improve Layering Between Console and Renderer ([sebmarkbage](https://github.com/sebmarkbage) in [#30925](https://github.com/facebook/react/pull/30925)) * Add Map for Server Component Logs ([sebmarkbage](https://github.com/sebmarkbage) in [#30905](https://github.com/facebook/react/pull/30905)) * Delete fiberToFiberInstanceMap ([sebmarkbage](https://github.com/sebmarkbage) in [#30900](https://github.com/facebook/react/pull/30900)) * Add Flight Renderer ([sebmarkbage](https://github.com/sebmarkbage) in [#30906](https://github.com/facebook/react/pull/30906)) * Refactor Error / Warning Count Tracking ([sebmarkbage](https://github.com/sebmarkbage) in [#30899](https://github.com/facebook/react/pull/30899)) * [flow] Upgrade Flow to 0.245.2 ([SamChou19815](https://github.com/SamChou19815) in [#30919](https://github.com/facebook/react/pull/30919)) * Separate RDT Fusebox into single-panel entry points ([huntie](https://github.com/huntie) in [#30708](https://github.com/facebook/react/pull/30708)) * Build Updater List from the Commit instead of Map ([sebmarkbage](https://github.com/sebmarkbage) in [#30897](https://github.com/facebook/react/pull/30897)) * Simplify Context Change Tracking in Profiler ([sebmarkbage](https://github.com/sebmarkbage) in [#30896](https://github.com/facebook/react/pull/30896)) * Remove use of .alternate in root and recordProfilingDurations ([sebmarkbage](https://github.com/sebmarkbage) in [#30895](https://github.com/facebook/react/pull/30895)) * Handle reordered contexts in Profiler ([sebmarkbage](https://github.com/sebmarkbage) in [#30887](https://github.com/facebook/react/pull/30887)) * Refactor Forcing Fallback / Error of Suspense / Error Boundaries ([sebmarkbage](https://github.com/sebmarkbage) in [#30870](https://github.com/facebook/react/pull/30870)) * Avoid getFiberIDUnsafe in debug() Helper ([sebmarkbage](https://github.com/sebmarkbage) in [#30878](https://github.com/facebook/react/pull/30878)) * Include some Filtered Fiber Instances ([sebmarkbage](https://github.com/sebmarkbage) in [#30865](https://github.com/facebook/react/pull/30865)) * Track root instances in a root Map ([sebmarkbage](https://github.com/sebmarkbage) in [#30875](https://github.com/facebook/react/pull/30875)) * Track all public HostInstances in a Map ([sebmarkbage](https://github.com/sebmarkbage) in [#30831](https://github.com/facebook/react/pull/30831)) * Support VirtualInstances in findAllCurrentHostInstances ([sebmarkbage](https://github.com/sebmarkbage) in [#30853](https://github.com/facebook/react/pull/30853)) * Add Filtering of Environment Names ([sebmarkbage](https://github.com/sebmarkbage) in [#30850](https://github.com/facebook/react/pull/30850)) * Support secondary environment name when it changes ([sebmarkbage](https://github.com/sebmarkbage) in [#30842](https://github.com/facebook/react/pull/30842)) * Increase max payload for websocket in standalone app ([runeb](https://github.com/runeb) in [#30848](https://github.com/facebook/react/pull/30848)) * Filter Server Components ([sebmarkbage](https://github.com/sebmarkbage) in [#30839](https://github.com/facebook/react/pull/30839)) * Track virtual instances on the tracked path for selections ([sebmarkbage](https://github.com/sebmarkbage) in [#30802](https://github.com/facebook/react/pull/30802)) * Remove displayName from inspected data ([sebmarkbage](https://github.com/sebmarkbage) in [#30841](https://github.com/facebook/react/pull/30841)) * chore[react-devtools/hook]: remove unused native values ([hoxyq](https://github.com/hoxyq) in [#30827](https://github.com/facebook/react/pull/30827)) * chore[react-devtools/extensions]: remove unused storage permission ([hoxyq](https://github.com/hoxyq) in [#30826](https://github.com/facebook/react/pull/30826)) * fix[react-devtools/extensions]: fixed tabs API calls and displaying restricted access popup ([hoxyq](https://github.com/hoxyq) in [#30825](https://github.com/facebook/react/pull/30825)) * feat[react-devtools]: support Manifest v3 for Firefox extension ([hoxyq](https://github.com/hoxyq) in [#30824](https://github.com/facebook/react/pull/30824)) * Reconcile Fibers Against Previous Children Instances ([sebmarkbage](https://github.com/sebmarkbage) in [#30822](https://github.com/facebook/react/pull/30822)) * Remove findCurrentFiberUsingSlowPathByFiberInstance ([sebmarkbage](https://github.com/sebmarkbage) in [#30818](https://github.com/facebook/react/pull/30818)) * Track Tree Base Duration of Virtual Instances ([sebmarkbage](https://github.com/sebmarkbage) in [#30817](https://github.com/facebook/react/pull/30817)) * Use Owner Stacks to Implement View Source of a Server Component ([sebmarkbage](https://github.com/sebmarkbage) in [#30798](https://github.com/facebook/react/pull/30798)) * Make function inspection instant ([sebmarkbage](https://github.com/sebmarkbage) in [#30786](https://github.com/facebook/react/pull/30786)) * Make Functions Clickable to Jump to Definition ([sebmarkbage](https://github.com/sebmarkbage) in [#30769](https://github.com/facebook/react/pull/30769)) * Support REACT_LEGACY_ELEMENT_TYPE for formatting JSX ([sebmarkbage](https://github.com/sebmarkbage) in [#30779](https://github.com/facebook/react/pull/30779)) * Find owners from the parent path that matches the Fiber or ReactComponentInfo ([sebmarkbage](https://github.com/sebmarkbage) in [#30717](https://github.com/facebook/react/pull/30717)) * [Flight/DevTools] Pass the Server Component's "key" as Part of the ReactComponentInfo ([sebmarkbage](https://github.com/sebmarkbage) in [#30703](https://github.com/facebook/react/pull/30703)) * Hide props section if it is null ([sebmarkbage](https://github.com/sebmarkbage) in [#30696](https://github.com/facebook/react/pull/30696)) * Support Server Components in Tree ([sebmarkbage](https://github.com/sebmarkbage) in [#30684](https://github.com/facebook/react/pull/30684)) * fix[react-devtools/InspectedElement]: fixed border stylings when some of the panels are not rendered ([hoxyq](https://github.com/hoxyq) in [#30676](https://github.com/facebook/react/pull/30676)) * Compute new reordered child set from the instance tree ([sebmarkbage](https://github.com/sebmarkbage) in [#30668](https://github.com/facebook/react/pull/30668)) * Unmount instance by walking the instance tree instead of the fiber tree ([sebmarkbage](https://github.com/sebmarkbage) in [#30665](https://github.com/facebook/react/pull/30665)) * Further Refactoring of Unmounts ([sebmarkbage](https://github.com/sebmarkbage) in [#30658](https://github.com/facebook/react/pull/30658)) * Remove lodash.throttle ([sebmarkbage](https://github.com/sebmarkbage) in [#30657](https://github.com/facebook/react/pull/30657)) * Unmount by walking previous nodes no longer in the new tree ([sebmarkbage](https://github.com/sebmarkbage) in [#30644](https://github.com/facebook/react/pull/30644)) * Build up DevTools Instance Shadow Tree ([sebmarkbage](https://github.com/sebmarkbage) in [#30625](https://github.com/facebook/react/pull/30625)) * chore[packages/react-devtools]: remove unused index.js ([hoxyq](https://github.com/hoxyq) in [#30579](https://github.com/facebook/react/pull/30579)) * Track DOM nodes to Fiber map for HostHoistable Resources ([sebmarkbage](https://github.com/sebmarkbage) in [#30590](https://github.com/facebook/react/pull/30590)) * Rename mountFiberRecursively/updateFiberRecursively ([sebmarkbage](https://github.com/sebmarkbage) in [#30586](https://github.com/facebook/react/pull/30586)) * Allow Highlighting/Inspect HostSingletons/Hoistables and Resources ([sebmarkbage](https://github.com/sebmarkbage) in [#30584](https://github.com/facebook/react/pull/30584)) * chore[react-devtools]: add global for native and use it to fork backend implementation ([hoxyq](https://github.com/hoxyq) in [#30533](https://github.com/facebook/react/pull/30533)) * Enable pointEvents while scrolling ([sebmarkbage](https://github.com/sebmarkbage) in [#30560](https://github.com/facebook/react/pull/30560)) * Make Element Inspection Feel Snappy ([sebmarkbage](https://github.com/sebmarkbage) in [#30555](https://github.com/facebook/react/pull/30555)) * Track the parent DevToolsInstance while mounting a tree ([sebmarkbage](https://github.com/sebmarkbage) in [#30542](https://github.com/facebook/react/pull/30542)) * Add DevToolsInstance to Store Stateful Information ([sebmarkbage](https://github.com/sebmarkbage) in [#30517](https://github.com/facebook/react/pull/30517)) * Implement "best renderer" by taking the inner most matched node ([sebmarkbage](https://github.com/sebmarkbage) in [#30494](https://github.com/facebook/react/pull/30494)) * Rename NativeElement to HostInstance in the Bridge ([sebmarkbage](https://github.com/sebmarkbage) in [#30491](https://github.com/facebook/react/pull/30491)) * Rename Fiber to Element in the Bridge Protocol and RendererInterface ([sebmarkbage](https://github.com/sebmarkbage) in [#30490](https://github.com/facebook/react/pull/30490)) * Stop filtering owner stacks ([sebmarkbage](https://github.com/sebmarkbage) in [#30438](https://github.com/facebook/react/pull/30438)) * [Fiber] Call life-cycles with a react-stack-bottom-frame stack frame ([sebmarkbage](https://github.com/sebmarkbage) in [#30429](https://github.com/facebook/react/pull/30429)) * [Flight] Prefix owner stacks added to the console.log with the current stack ([sebmarkbage](https://github.com/sebmarkbage) in [#30427](https://github.com/facebook/react/pull/30427)) * [BE] switch to hermes parser for prettier ([kassens](https://github.com/kassens) in [#30421](https://github.com/facebook/react/pull/30421)) * Implement Owner Stacks ([sebmarkbage](https://github.com/sebmarkbage) in [#30417](https://github.com/facebook/react/pull/30417)) * [BE] upgrade prettier to 3.3.3 ([kassens](https://github.com/kassens) in [#30420](https://github.com/facebook/react/pull/30420)) * [ci] Add yarn_test_build job to gh actions * [Fizz] Refactor Component Stack Nodes ([sebmarkbage](https://github.com/sebmarkbage) in [#30298](https://github.com/facebook/react/pull/30298)) * Print component stacks as error objects to get source mapping ([sebmarkbage](https://github.com/sebmarkbage) in [#30289](https://github.com/facebook/react/pull/30289)) * Upgrade flow to 0.235.0 ([kassens](https://github.com/kassens) in [#30118](https://github.com/facebook/react/pull/30118)) * fix: path handling in react devtools ([Jack-Works](https://github.com/Jack-Works) in [#29199](https://github.com/facebook/react/pull/29199))
React ·

React is a JavaScript library for building user interfaces.
- Declarative: React makes it painless to create interactive UIs. Design simple views for each state in your application, and React will efficiently update and render just the right components when your data changes. Declarative views make your code more predictable, simpler to understand, and easier to debug.
- Component-Based: Build encapsulated components that manage their own state, then compose them to make complex UIs. Since component logic is written in JavaScript instead of templates, you can easily pass rich data through your app and keep the state out of the DOM.
- Learn Once, Write Anywhere: We don't make assumptions about the rest of your technology stack, so you can develop new features in React without rewriting existing code. React can also render on the server using Node and power mobile apps using React Native.
Learn how to use React in your project.
Installation
React has been designed for gradual adoption from the start, and you can use as little or as much React as you need:
- Use Quick Start to get a taste of React.
- Add React to an Existing Project to use as little or as much React as you need.
- Create a New React App if you're looking for a powerful JavaScript toolchain.
Documentation
You can find the React documentation on the website.
Check out the Getting Started page for a quick overview.
The documentation is divided into several sections:
- Quick Start
- Tutorial
- Thinking in React
- Installation
- Describing the UI
- Adding Interactivity
- Managing State
- Advanced Guides
- API Reference
- Where to Get Support
- Contributing Guide
You can improve it by sending pull requests to this repository.
Examples
We have several examples on the website. Here is the first one to get you started:
import { createRoot } from 'react-dom/client';
function HelloMessage({ name }) {
return <div>Hello {name}</div>;
}
const root = createRoot(document.getElementById('container'));
root.render(<HelloMessage name="Taylor" />);
This example will render "Hello Taylor" into a container on the page.
You'll notice that we used an HTML-like syntax; we call it JSX. JSX is not required to use React, but it makes code more readable, and writing it feels like writing HTML.
Contributing
The main purpose of this repository is to continue evolving React core, making it faster and easier to use. Development of React happens in the open on GitHub, and we are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can take part in improving React.
Code of Conduct
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
Contributing Guide
Read our contributing guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React.
Good First Issues
To help you get your feet wet and get you familiar with our contribution process, we have a list of good first issues that contain bugs that have a relatively limited scope. This is a great place to get started.
License
React is MIT licensed.