Ember 4.2 Released

– By Jared Galanis, Ricardo Mendes, Jen Weber

Today the Ember project is releasing version 4.2 of Ember.js, Ember Data, and Ember CLI.

This release kicks off the 4.3 beta cycle for all sub-projects. We encourage our community (especially addon authors) to help test these beta builds and report any bugs before they are published as a final release in six weeks' time. The ember-try addon is a great way to continuously test your projects against the latest Ember releases.

You can read more about our general release process here:


Ember.js is the core framework for building ambitious web applications.

Changes in Ember.js 4.2

Ember.js 4.2 is an incremental, backwards compatible release of Ember with bug fixes, performance improvements, and minor deprecations.

Bug Fixes

Ember.js 4.2 introduced 1 bug fix.

Class-based helpers are now allowed to work in strict-mode. (#19878)


Ember.js 4.2 introduced 0 features.


Ember.js 4.2 introduced 0 deprecations.

For more details on changes in Ember.js 4.2, please review the Ember.js 4.2.0 release page.

Ember Data

Ember Data is the official data persistence library for Ember.js applications.

Changes in Ember Data 4.2

Bug Fixes

Ember Data 4.2 introduced 3 bug fixes and some tests and documentation improvements.

  • Update @ember/string to the latest version. The prior version used deprecated import paths that error under ember-source v4.0.
  • Bugfix for Embroider compatibility. Ensure shouldCompileModules is respected.
  • Resolve deprecated usage of assign.


Ember Data 4.2 introduced 0 features.


Ember Data 4.2 introduced 0 deprecations.

Support for the toJSON method on Ember Data records has been removed. It was deprecated in 3.x and slated for removal in 4.x. If your app uses this method, follow the deprecation guide.

For more details on changes in Ember Data 4.2, please review the Ember Data 4.2.0 commits.

Ember CLI

Ember CLI is the command line interface for managing and packaging Ember.js applications.

Upgrading Ember CLI

You may upgrade Ember CLI using the ember-cli-update project:

npx ember-cli-update

This utility will help you to update your app or addon to the latest Ember CLI version. You will probably encounter merge conflicts, in which the default behavior is to let you resolve conflicts on your own. For more information on the ember-cli-update project, see the GitHub README.

While it is recommended to keep Ember CLI versions in sync with Ember and Ember Data, this is not required. After updating ember-cli, you can keep your current version(s) of Ember or Ember Data by editing package.json to revert the changes to the lines containing ember-source and ember-data.

Changes in Ember CLI 4.2

Bug Fixes

Ember CLI 4.2 introduced 3 bug fixes:

  1. Updated mentions of the Ember CLI website to the new URL. (#9681)
  2. Stale GitHub Actions workflows are cancelled when starting a new one. (#9726)
  3. ember-template-lint dependency in default blueprints has been upgraded to v4. (#9753)


Ember CLI 4.2 introduced 1 feature.

  1. Add an assert and a deprecate utility. (#9731)


Ember CLI 4.2 introduced 0 deprecations.

For more details on the changes in Ember CLI 4.2 and detailed upgrade instructions, please review the Ember CLI 4.2.0 release page.

Thank You!

As a community-driven open-source project with an ambitious scope, each of these releases serves as a reminder that the Ember project would not have been possible without your continued support. We are extremely grateful to our contributors for their efforts.