React Query StaleTime: Optimizing Data Fetching in React Applications

One of the key concepts of React Query is staleTime, which determines how long a piece of fetched data is considered fresh before it needs to be refetched.

What is staleTime in React Query?

staleTime is a configuration option in React Query that specifies the duration (in milliseconds) for which the fetched data is considered fresh. During this period, React Query won't automatically refetch the data. This helps improve performance and by reducing unnecessary network requests.

Default behavior

By default, staleTime is set to zero, meaning the data is considered stale immediately after it's fetched. This setting ensures data is always up-to-date but can lead to frequent refetching.

useQuery('todos', fetchTodos)

How to customize staleTime in React query

You can customize staleTime to suit your application's needs. Setting a longer staleTime reduces the frequency of network requests, which can be beneficial for data that doesn't change often.

useQuery('todos', fetchTodos, { staleTime: 1000 * 60 * 5 }) // 5 minutes

When to use staleTime

Static data

For data that rarely changes, like a user's profile information, you can set a longer staleTime to improve performance.

Dynamic data

For frequently updating data, like real-time notifications, a shorter staleTime or the default setting is more appropriate.

Advanced staleTime strategies

Conditional staleTime

You can dynamically adjust staleTime based on factors like user behavior or network status. For example, increasing staleTime when the user is offline.

const staleTime = isOffline ? 1000 * 60 * 30 : 1000 * 60 * 5;
useQuery('todos', fetchTodos, { staleTime })

Incremental staleTime

Implementing an incremental staleTime that increases over time can be useful for data that becomes less relevant as it ages.