SWR
A React hook library for fetching data, with caching and automatic refresh.
- Stars
- 32.5k
- Forks
- 1.4k
- Licence
- MIT
- Language
- TypeScript
- Last update
- 20 days ago
- Type
- Library
What it is
SWR is a React Hooks library for loading data in web interfaces. Its name comes from stale-while-revalidate: it shows cached data first, requests fresh data in the background, then updates the screen when the new data arrives. Developers use it to simplify data loading logic in React components.
- Load a user profile from an API with a single useSWR call that returns data, error, and loading state
- Show cached content immediately while refreshing it in the background
- Poll an endpoint at intervals to keep a view up to date
- Apply optimistic updates to local data before the server responds
- Paginate lists and recover scroll position
Great for
- React developers who fetch data from APIs in components
- Projects that want built-in caching and request deduplication
- Apps that need data to refresh on focus, network recovery, or polling
- Teams building React Native or Next.js interfaces
Not ideal for
- People who do not write React code, since the library is built around React Hooks
- Projects that need a full server-side data layer rather than client-side fetching hooks
- Beginners with no JavaScript or React experience, who would need to learn those first
How to get it
- 1
Install with a package manager
You'll need: Node.js and a package manager such as npm · React
Install the package
npm install swr - 2
Run it
- Install swr in a React project.
- Import useSWR from 'swr' in a component.
- Pass a unique key (often an API URL) and a fetcher function.
- Use the returned data, error, and isLoading values to render the UI.
- 3
Get the most out of it
- Read the full documentation at swr.vercel.app for options such as polling, retry, and pagination
- Use the key as a unique request identifier so identical requests are deduplicated
- Use the fetcher function to plug in your preferred data-fetching library
- Review the SSR and SSG support described in the README if you use server rendering
Downloads
Strengths
- Small, focused API: one hook covers the common fetch, loading, and error cases
- Built-in cache and request deduplication reduce repeated network calls
- Works with any asynchronous fetcher, so you can use your preferred fetching library
Trade-offs
- Requires React knowledge; it is not useful outside React-style apps
- The README is brief and points to the external documentation site for details and examples
- Behavior such as caching and revalidation has settings that take time to learn
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| swr (this) | 32.5k | Library | intermediate | 20 days ago | React developers who fetch data from APIs in components |
| query | 50.5k | Library | intermediate | 4 days ago | Frontend developers building apps that load data from a server |
| apollo-client | 19.8k | Library | intermediate | 5 days ago | Developers building React apps that query a GraphQL API |
| usehooks | 11.5k | Library | beginner | 1.5 years ago | React developers who want ready-made hooks for common browser tasks |
| NativeBase | 20.4k | Library | intermediate | 9 months ago | Teams maintaining an existing app already built on NativeBase |
| next.js | 143k | Framework | intermediate | 4 days ago | Developers already comfortable with React who want a full framework around it |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.