2019-07-22
1578
#node
Brian De Sousa
3860
Jul 22, 2019 â‹… 5 min read

ES modules in Node.js 12, from experimental to release

Brian De Sousa Geek. Dad. Husband. Developer. Traveler.

Recent posts:

Stagehand and Gemini logos on a gradient background symbolizing AI web automation

How to build a web-based AI agent with Stagehand and Gemini

This guide walks you through creating a web UI for an AI agent that browses, clicks, and extracts info from websites powered by Stagehand and Gemini.

Elijah Asaolu
Jul 4, 2025 â‹… 8 min read
Getting Started With Claude 4 API: A Developer's Walkthrough

Getting started with Claude 4 API: A developer’s walkthrough

This guide explores how to use Anthropic’s Claude 4 models, including Opus 4 and Sonnet 4, to build AI-powered applications.

Andrew Baisden
Jul 3, 2025 â‹… 16 min read
ai dev tool power rankings

AI dev tool power rankings & comparison [July 2025 edition]

Which AI frontend dev tool reigns supreme in July 2025? Check out our power rankings and use our interactive comparison tool to find out.

Chizaram Ken
Jul 2, 2025 â‹… 3 min read
how API client automation can save you hours in development

How API client automation can save you hours in development

Learn how OpenAPI can automate API client generation to save time, reduce bugs, and streamline how your frontend app talks to backend APIs.

Lewis Cianci
Jul 1, 2025 â‹… 7 min read
View all posts

5 Replies to "ES modules in Node.js 12, from experimental to release"

  1. Thank you for clarification! And one question is still not covered: why .mjs? Does it mean we should have both identical. js and mjs files in a package for browsers/babel and node?

  2. From what I understand, NodeJS developers considered several options for being able to suppor ES modules alongside existing CommonJS modules including not using the .mjs extension. At the end of the day, I believe the decision was made to use the .mjs extension because it was a simply way to identify an ES module over plain JavaScript or CommonJS modules. It also sort of fits in the JavaScript community with other frameworks and tools using file extensions as meta-data (ex. typescript uses .ts, react has .jsx, etc.). Here’s a great write up on other options that were considered: https://2ality.com/2017/05/es-module-specifiers.html.

    Browsers will be able to load modules from .mjs files as well but the .mjs extension will not identify that a script contains an ES module. In the browser, you’ll need to include the type=”module” attribute on your script tags, for example:

    http://./script.mjs

Leave a Reply