Fixing Could not find module @angular-devkit/build-angular error in Angular

If you update your Angular application to newer version you might get Could not find module @angular-devkit/build-angular error while building or running the application.

This package @angular-devkit/build-angular is introduced in Angular 6.0 as a dev dependency.

So if you upgrade your application from older version of Angular to Angular 6 or higher, there is a chance that you will get this error.

Unfortunately there is no straight way to fix this issue. We have to try different ways as mentioned below.

To fix Could not find module @angular-devkit/build-angular error in Angular follow the below steps

1. Delete node_modules folder and run npm install
2. Install @angular-devkit/build-angular package as a dev dependency.
3. Reinstall @angular/cli

Solution 1: Delete node_modules folder and run npm install

If you are upgrading from older version to newer version the package.json file will be updated accordingly.

But our local Angular application will have older versions of packages installed in node_modules folder.

So delete the node_modules folder manually from the application directory.

After that clear the cache using npm cache clean --verify.

And then run npm install command.

As package.json will have latest updated versions, npm will install all the required packages again to run the Angular application.

Solution 2 : Install @angular-devkit/build-angular package as a dev dependency

If the above method is not working, then install @angular-devkit/build-angular package as dev dependency in the new versions of Angular.

npm install --save-dev @angular-devkit/build-angular

or if you use yarn run the below command.

yarn add @angular-devkit/build-angular --dev

Further you might need to run npm audit fix --force command also.

Solution 3: Re-install @angular/cli

Further you can try to re-install Angular cli to fix Could not find module @angular-devkit/build-angular error.

Follow the below steps to re-install Angular CLI.

1. Uninstall Angular CLI npm uninstall -g @angular/cli
2. Clear the npm cache npm cache clean --force
3. Install Angular CLI again npm install -g @angular/cli@latest
4. Run npm install again.
5. Finally run the application using ng build or ng serve