How to Update an Angular Project from Version 12 to Version 17

The Code Points March 16, 2025 0

Upgrading your Angular project to the latest version is crucial for taking advantage of new features, improved performance, better security, and bug fixes. Angular frequently releases updates with new functionality, and it's essential to stay up to date to ensure your application remains reliable and competitive.

In this blog, we’ll walk you through the process of upgrading your Angular project from version 12 to version 17. This guide will cover the necessary steps, tools, and considerations to make the migration as smooth as possible.

Step 1: Preparation and Backup

Before starting the upgrade process, backing up your project is essential. It ensures that you have a fallback option in case anything goes wrong during the upgrade process.

1.1 Backup Your Project

Ensure you have a backup of your project, either by committing all changes to your version control system (like Git) or creating a local copy.

git commit -am "Backup before upgrading Angular"
git push origin main

1.2 Review Dependencies

Make a list of your current dependencies in the package.json file. This can help you identify any major dependencies that may need updates to support Angular 17. Make sure you are using the latest version of Node.js, as Angular 17 may have updated Node.js requirements.

Step 2: Upgrade Angular CLI

The first step to upgrading Angular is to update the Angular CLI globally and locally in your project. Angular CLI is responsible for managing your Angular projects and is essential for building, serving, and testing your Angular apps.

2.1 Update Global Angular CLI

To ensure that you're using the latest version of Angular CLI, you should update it globally:

npm install -g @angular/cli@17

2.2 Update Local Angular CLI

Next, you should update the Angular CLI version in your project:

npm install @angular/cli@17 --save-dev

This will update the CLI version used in your project to match the global version.

Step 3: Update Angular Core and Dependencies

Now that the Angular CLI is updated, it’s time to update the core Angular framework along with other dependencies.

3.1 Update Angular Core

You can use the Angular Update Guide provided by the Angular team to get a list of all breaking changes and recommended steps for updating. It’s a useful tool for checking whether you need to update specific code or configurations.

To update Angular Core and its related packages (like Angular Forms, Angular Router, etc.), run the following command:

ng update @angular/core@17 @angular/cli@17

This command will automatically update the Angular core packages and ensure compatibility with Angular 17.

3.2 Update Other Dependencies

Next, you should update other dependencies that might need to be updated to match the new Angular version. You can run the following command to see which packages need updates:

ng update

This will list all the outdated dependencies. You can update the dependencies one by one or use the ng update command to upgrade them in bulk.

ng update --all --force

Note: Be cautious when using the --force flag, as it may update some packages that are not compatible with Angular 17.

Step 4: Fix Breaking Changes and Code Adjustments

With the major update done, there might be some breaking changes or deprecations that you need to address. Some APIs may have been removed or modified in the new version.

4.1 Review the Angular Update Guide

To identify and resolve breaking changes, it’s a good idea to review the Angular Update Guide. This tool provides a detailed breakdown of changes between Angular versions, including recommended steps to handle deprecated features or APIs.

4.2 Refactor Deprecated Code

Some code from Angular 12 may have been deprecated and removed in Angular 17. If any of your code relies on deprecated features, you’ll need to refactor it. Pay attention to the following:

• Removed APIs: Some features might be completely removed, so you’ll need to replace them with new alternatives.
• Deprecations: Features that are marked as deprecated may still work in Angular 17, but it’s a good idea to start migrating to newer alternatives.

For example, Angular 17 could have changes in services, lifecycle hooks, or routing, so it's important to check your code for these.

Step 5: Update Styles and Templates

Angular’s upgrade process often includes changes to the way templates and styles are processed. You may need to update your components, modules, and templates to comply with Angular 17’s new syntax.

5.1 Update Template Syntax

Check if there are any changes to template syntax, such as stricter binding checks or new directives. These can affect how your templates are structured.

5.2 Update Stylesheets

Angular 17 might also introduce changes to how stylesheets are processed, particularly with the introduction of new CSS features or component styling mechanisms. Make sure to check the Angular changelog for any updates in this area.

Step 6: Run Tests and Build the Project

After updating the dependencies and resolving breaking changes, it's important to ensure that everything works correctly by running your tests and building the project.

6.1 Run Unit and End-to-End Tests

Ensure that your unit tests and end-to-end tests pass after the upgrade:

ng test
ng e2e

Fix any failing tests related to deprecated methods or syntax changes.

6.2 Build the Project

Finally, run a production build to ensure that everything compiles and works as expected:

ng build --prod

If the build is successful, you’ve completed the upgrade process!

Step 7: Deployment

Once everything is working correctly locally, you can deploy your updated application to your staging or production environment. Make sure to test it in a live environment before fully rolling out the update.

Conclusion

Upgrading an Angular project from version 12 to version 17 is a process that involves updating Angular CLI, core dependencies, resolving breaking changes, and testing your application. By following the outlined steps, you can ensure that your Angular project is up-to-date with the latest features, performance improvements, and security patches.

While the upgrade process may seem daunting, the Angular team provides robust tools, like the Angular Update Guide and detailed changelogs, to make the migration as smooth as possible. By taking the time to thoroughly test your application after the upgrade and addressing any deprecated features, you can enjoy all the new benefits that come with Angular 17.