JSON Modules in JavaScript

ES Modules were introduced in ES2015. The import and export keywords by default are only applicable to JavaScript code. But there is a new proposal to allow it to be used for JSON modules in JavaScript.

It is convenient to keep some configuration inside a JSON file and import that. And this was possible using the commonjs module format. The proposal will allow us to do import JSON Modules in an ES module.

- Advertisement -

Let us assume we have a configuration file called configuration.js. The following will give an error by default:

import config from './configuration.json';

Node.js will throw the following error:

TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".json"

JSON modules proposal

The proposal now allows us to import JSON modules using an import assertion.

import jsonObject from "./file.json" assert { type: "json" };

assert { type: “json” } is what is defined as an import assertion that specifies the type of the module and how it should be parsed and imported as.

The jsonObject variable will contain the JavaScript object obtained after parsing the file.

Note: named imports are not available for JSON modules.

It is also possible to import JSON modules dynamically.

const { default: jsonObject } = await import('./file.json', {
  assert: {
    type: 'json'


JSON modules currently work in Node.js >=17.1 by using the –experimental-json-modules flag.

node --experimental-json-modules index.mjs

For browsers, Chrome 91 already has support for JSON modules and others should implement it soon.

Recent Articles

How to sort a Set in JavaScript

ES6 introduced the set data structure in JavaScript. But sets are not ordered abstract data structures. So there is no .sort() property...

Debugging CSS scroll using one simple style

I have been doing a lot of complicated front-end work off lately and that always brings me back to the class conundrum...

CSS :has a parent selector now

CSS now includes a :has selector that allows us to apply styles on the basis of what is happening inside an element....

How to fix “invalid active developer path” after MacOS update

If you are here, then you are getting an "invalid active developer path" error on running commands in the terminal after a...

Getting the value of an input element as a number without parseInt

Every once in a while, you come across something and you think, how did I not know this earlier? valueAsNumber is that thing...

Related Stories

Leave A Reply

Please enter your comment!
Please enter your name here

Hi there! Want some more knowledge?

Think that the knowledge shared is helpful? You might want to give our mailing list a try. We'll send you 2-4 emails a month, right when new posts come out.