use-local-storage-state

React hook that persist data in localStorage

Install

React 18 and above:

npm install use-local-storage-state

⚠️ React 17 and below. For docs, go to the react-17 branch.

npm install use-local-storage-state@17

Why

• Actively maintained for the past 4 years — see contributors page.
• Production ready.
• React 18 concurrent rendering support.
• SSR support.
• Handles the Window storage event and updates changes across browser tabs, windows, and iframe's. Disable with storageSync: false.
• In-memory fallback when localStorage throws an error and can't store the data. Provides a isPersistent API to let you notify the user their data isn't currently being stored.
• Aiming for high-quality with my open-source principles.

Usage

import useLocalStorageState from 'use-local-storage-state'

export default function Todos() {
    const [todos, setTodos] = useLocalStorageState('todos', {
        defaultValue: ['buy avocado', 'do 50 push-ups']
    })
}

You can experiment with the example here.

import React, { useState } from 'react'
import useLocalStorageState from 'use-local-storage-state'

export default function Todos() {
    const [todos, setTodos] = useLocalStorageState('todos', {
        defaultValue: ['buy avocado']
    })
    const [query, setQuery] = useState('')

    function onClick() {
        setQuery('')
        setTodos([...todos, query])
    }

    return (
        <>
            <input value={query} onChange={e => setQuery(e.target.value)} />
            <button onClick={onClick}>Create</button>
            {todos.map(todo => (
                <div>{todo}</div>
            ))}
        </>
    )
}

There are a few cases when localStorage isn't available. The isPersistent property tells you if the data is persisted in localStorage or in-memory. Useful when you want to notify the user that their data won't be persisted.

import React, { useState } from 'react'
import useLocalStorageState from 'use-local-storage-state'

export default function Todos() {
    const [todos, setTodos, { isPersistent }] = useLocalStorageState('todos', {
        defaultValue: ['buy avocado']
    })

    return (
        <>
            {todos.map(todo => (<div>{todo}</div>))}
            {!isPersistent && <span>Changes aren't currently persisted.</span>}
        </>
    )
}

The removeItem() method will reset the value to its default and will remove the key from the localStorage. It returns to the same state as when the hook was initially created.

import useLocalStorageState from 'use-local-storage-state'

export default function Todos() {
    const [todos, setTodos, { removeItem }] = useLocalStorageState('todos', {
        defaultValue: ['buy avocado']
    })

    function onClick() {
        removeItem()
    }
}

If you are hydrating your component (for example, if you are using Next.js), your component might re-render twice. This is behavior specific to React and not to this library. It's caused by the useSyncExternalStore() hook. There is no workaround. This has been discussed in the issues: https://github.com/astoilkov/use-local-storage-state/issues/56.

If you want to know if you are currently rendering the server value you can use this helper function:

function useIsServerRender() {
  return useSyncExternalStore(() => {
    return () => {}
  }, () => false, () => true)
}

API

useLocalStorageState(key: string, options?: LocalStorageOptions)

Returns [value, setValue, { removeItem, isPersistent }] when called. The first two values are the same as useState(). The third value contains two extra properties:

• removeItem() — calls localStorage.removeItem(key) and resets the hook to it's default state
• isPersistent — boolean property that returns false if localStorage is throwing an error and the data is stored only in-memory

key

Type: string

The key used when calling localStorage.setItem(key) and localStorage.getItem(key).

⚠️ Be careful with name conflicts as it is possible to access a property which is already in localStorage that was created from another place in the codebase or in an old version of the application.

options.defaultValue

Type: any

Default: undefined

The default value. You can think of it as the same as useState(defaultValue).

options.storageSync

Type: boolean

Default: true

Setting to false doesn't subscribe to the Window storage event. If you set to false, updates won't be synchronized across tabs, windows and iframes.

options.serializer

Type: { stringify, parse }

Default: JSON

JSON does not serialize Date, Regex, or BigInt data. You can pass in superjson or other JSON-compatible serialization library for more advanced serialization.

Related

• use-session-storage-state — A clone of this library but for sessionStorage.
• local-db-storage — Tiny wrapper around IndexedDB that mimics localStorage API.