This is a super-simple-small promise-based keyval store implemented with IndexedDB, largely based on async-storage by Mozilla.

localForage offers similar functionality, but supports older browsers with broken/absent IDB implementations. Because of that, it's 7.4k, whereas idb-keyval is < 600 bytes. Also, it's tree-shaking friendly, so you'll probably end up using fewer than 500 bytes. Pick whichever works best for you!

This is only a keyval store. If you need to do more complex things like iteration & indexing, check out IDB on NPM (a little heavier at 1.7k). The first example in its README is how to recreate this library.

import { set } from 'idb-keyval';

set('hello', 'world');
set('foo', 'bar');

Since this is IDB-backed, you can store anything structured-clonable (numbers, arrays, objects, dates, blobs etc).

All methods return promises:

import { set } from 'idb-keyval';

set('hello', 'world')
  .then(() => console.log('It worked!'))
  .catch(err => console.log('It failed!', err));

import { get } from 'idb-keyval';

// logs: "world"
get('hello').then(val => console.log(val));

If there is no 'hello' key, then val will be undefined.

import { keys } from 'idb-keyval';

// logs: ["hello", "foo"]
keys().then(keys => console.log(keys));

import { del } from 'idb-keyval';

del('hello');

import { clear } from 'idb-keyval';

clear();

By default, the methods above use an IndexedDB database named keyval-store and an object store named keyval. You can create your own store, and pass it as an additional parameter to any of the above methods:

import { Store, set } from 'idb-keyval';

const customStore = new Store('custom-db-name', 'custom-store-name');
set('foo', 'bar', customStore);

That's it!

npm install idb-keyval

Now you can require/import idb-keyval:

import { get, set } from 'idb-keyval';

• dist/idb-keyval.mjs is a valid JS module.
• dist/idb-keyval-iife.js can be used in browsers that don't support modules. idbKeyval is created as a global.
• dist/idb-keyval-iife.min.js As above, but minified.
• dist/idb-keyval-iife-compat.min.js As above, but works in older browsers such as IE 10.
• dist/idb-keyval-amd.js is an AMD module.
• dist/idb-keyval-amd.min.js As above, but minified.

These built versions are also available on jsDelivr, e.g.:

<script src="https://cdn.jsdelivr.net/npm/idb-keyval@3/dist/idb-keyval-iife.min.js"></script>
<!-- Or in modern browsers: -->
<script type="module">
  import { get, set } from 'https://cdn.jsdelivr.net/npm/idb-keyval@3/dist/idb-keyval.mjs';
</script>

2.x exported an object with methods:

// This no longer works in 3.x
import idbKeyval from 'idb-keyval';

idbKeyval.set('foo', 'bar');

Whereas in 3.x you import the methods directly:

import { set } from 'idb-keyval';

set('foo', 'bar');

This is better for minification, and allows tree shaking.