browser-cookie-utils

Appearance

JSON cookies 2.1.0+ ​

js
import { setJSONCookie, getJSONCookie } from 'browser-cookie-utils';

setJSONCookie('prefs', { theme: 'dark', fontSize: 14 }, { unit: 'month' });

getJSONCookie('prefs'); // { theme: 'dark', fontSize: 14 }
  • setJSONCookie(name, value, options) takes the same options as setCookie and returns the same result. Nothing is written (and false is returned) if the value can't be serialized: circular references, BigInt, undefined, functions.
  • getJSONCookie(name) returns the parsed value, or null if the cookie is missing or isn't valid JSON. __proto__ keys are dropped.
  • In TypeScript, pass the expected type: getJSONCookie<Prefs>('prefs').

Size

Browsers limit each cookie to about 4 KB after URI encoding, and JSON grows when encoded. Keep JSON cookies small.