Modules: ECMAScript modules#

Added in: v8.5.0
History
VersionChanges
v23.1.0, v22.12.0, v20.18.3, v18.20.5

Import attributes are no longer experimental.

v22.0.0

Drop support for import assertions.

v21.0.0, v20.10.0, v18.20.0

Add experimental support for import attributes.

v20.0.0, v18.19.0

Module customization hooks are executed off the main thread.

v18.6.0, v16.17.0

Add support for chaining module customization hooks.

v17.1.0, v16.14.0

Add experimental support for import assertions.

v17.0.0, v16.12.0

Consolidate customization hooks, removed getFormat, getSource, transformSource, and getGlobalPreloadCode hooks added load and globalPreload hooks allowed returning format from either resolve or load hooks.

v15.3.0, v14.17.0, v12.22.0

Stabilize modules implementation.

v14.13.0, v12.20.0

Support for detection of CommonJS named exports.

v14.8.0

Unflag Top-Level Await.

v14.0.0, v13.14.0, v12.20.0

Remove experimental modules warning.

v13.2.0, v12.17.0

Loading ECMAScript modules no longer requires a command-line flag.

v12.0.0

Add support for ES modules using .js file extension via package.json "type" field.

Stability: 2 - Stable

Introduction#

ECMAScript modules are the official standard format to package JavaScript code for reuse. Modules are defined using a variety of import and export statements.

The following example of an ES module exports a function:

// addTwo.mjs
function addTwo(num) {
  return num + 2