# Angular CLI: Could not find the '@angular-devkit/build-angular:browser' builder's node package / Cannot find module '@angular-devkit/build-angular/package.json'

**Code:** `Could not find the builder's node package` · **Category:** Angular · **Seen on:** Angular, Angular CLI, npm

The build tooling package is missing from `node_modules` — dependencies were not installed or the lockfile/install is broken.

## Meaning

`ng serve` and `ng build` load the builder from `@angular-devkit/build-angular` (or `@angular/build`). If `node_modules` was deleted, `npm install` failed partway, devDependencies were skipped (`NODE_ENV=production`), or the package was removed, the CLI cannot find it.

## Common causes

- `npm install` not run after cloning
- Install skipped devDependencies (production mode)
- Package removed or version mismatch after an upgrade
- Corrupted `node_modules` or a failed install
- Builder changed (esbuild `@angular/build`) but angular.json still points at the old one

## Quick fix

1. Run `npm install` (install devDependencies too)
2. Delete `node_modules` and the lockfile if corrupted, then reinstall
3. Install the builder: `npm i -D @angular-devkit/build-angular`

## Detailed fix by platform

### npm

1. `rm -rf node_modules && npm ci` (or `npm install`)
2. Make sure devDependencies install: `npm install --include=dev`

### Angular CLI

1. `ng update @angular/cli @angular/core` to align builder versions

## How to diagnose

1. **Folder** — Does node_modules/@angular-devkit exist?
2. **Install** — Did npm install finish without errors?
3. **Mode** — NODE_ENV=production skipping dev dependencies?

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Source: [WhatIsMyError](https://whatismyerror.com/errors/angular/cannot-find-module-angular-devkit-build-angular)