Downgrading Angular 16 to 15

Question

I have downgraded angular 16 to 15 but some components are still at original version 16.2.12 (animations, common, compiler, compiler-cli, core, forms):

Angular CLI: 15.0.0
Node: 16.14.0
Package Manager: npm 8.3.1
OS: win32 x64

Angular: 16.2.12
... animations, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router

Package                            Version
------------------------------------------------------------
@angular-devkit/architect          0.1602.10
@angular-devkit/build-angular      16.2.10
@angular-devkit/core               15.0.0
@angular-devkit/schematics         15.0.0 (cli-only)
@angular/cdk                       15.0.0
@angular/material                  15.0.0
@angular/material-moment-adapter   15.0.0
@schematics/angular                15.0.0 (cli-only)
typescript                         5.1.6

How do I remove all references to version 16.2.12?

My package.json look like the following:

  "dependencies": {
    "@angular-devkit/core": "^15.0.0",
    "@angular-material-components/datetime-picker": "16.0.*",
    "@angular-material-components/moment-adapter": "^16.0.1",
    "@angular/animations": "^16.2.12",
    "@angular/cdk": "^15.0.0",
    "@angular/common": "^16.2.12",
    "@angular/compiler": "^16.2.12",
    "@angular/core": "^16.2.12",
    "@angular/forms": "^16.2.12",
    "@angular/material": "^15.0.0",
    "@angular/material-moment-adapter": "^15.0.0",
    "@angular/platform-browser": "^16.2.12",
    "@angular/platform-browser-dynamic": "^16.2.12",
    "@angular/router": "^16.2.12",
    "@mat-datetimepicker/core": "^12.0.1",
    "@microsoft/signalr": "^7.0.4",
    "@popperjs/core": "^2.11.6",
    "automapper-ts": "^1.9.0",
    "bootstrap": "^5.2.3",
    "file-saver": "^2.0.5",
    "google-libphonenumber": "^3.2.33",
    "hammerjs": "^2.0.8",
    "moment": "^2.29.4",
    "ngx-cookie-service": "^16.1.0",
    "tslib": "^2.3.0",
    "zone.js": "^0.13.3"
  },

The dev section is as follows:

 "devDependencies": {
    "@angular-devkit/build-angular": "^16.2.10",
    "@angular/compiler-cli": "^16.2.12",
    "@types/google-libphonenumber": "^7.4.28",
    "@types/jasmine": "~4.0.0",
    "jasmine-core": "~4.1.0",
    "karma": "~6.3.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage": "~2.2.0",
    "karma-jasmine": "~5.0.0",
    "karma-jasmine-html-reporter": "~1.7.0",
    "typescript": "^5.1.6"
  }

Answer 1

First install the angular 15 cli.

npm i -g @angular/cli@15

Then create a new angular project

ng new Angular15App

After creating run npm install

npm install

Now all your versions will be synced to angular 15, now install all the packages from your old project into the new project, this will give you the version numbers that suit angular 15

Finally once all the packages are installed, copy paste the new package.json version values into your original project, this will help you solve your problem!

Answer 2

Looking at your package.json, the following packages need to be downgraded to angular 15

"@angular-material-components/datetime-picker": "16.0.*",
"@angular-material-components/moment-adapter": "^16.0.1",
"@angular/animations": "^16.2.12",
"@angular/common": "^16.2.12",
"@angular/compiler": "^16.2.12",
"@angular/core": "^16.2.12",
"@angular/forms": "^16.2.12",
"@angular/platform-browser-dynamic": "^16.2.12",
"@angular/router": "^16.2.12",

In the dev dependencies section, the following packages need to downgrade

 "@angular-devkit/build-angular": "^16.2.10",

To downgrade first you need uninstall angular cli and then do the following command

npm uninstall -g @angular/cli
npm cache clean
npm install -g @angular/cli@15

You can find the version 15 from here

https://www.npmjs.com/

Answer 3

first you can do like this, for downgrade version 16 to 15

npm uninstall @angular/cli
sudo npm install @angular/cli@15

and then check your angular version

ng version

if angular version 15, you need adjust your package.json, please adjust version with information from ng version, but if you have repository angular version 15, you don't need adjust package again

"dependencies": {
    "@angular-devkit/core": "^15.0.0",
    "@angular/animations": "^15.0.0",
    "@angular/cdk": "^15.0.0",
    "@angular/common": "^15.0.0",
    "@angular/compiler": "^15.0.0",
    "@angular/core": "^15.0.0",
    "@angular/forms": "^15.0.0",
    "@angular/material": "^15.0.0",
    "@angular/material-moment-adapter": "^15.0.0",
    "@angular/platform-browser": "^15.0.0",
    "@angular/platform-browser-dynamic": "^15.0.0",
    "@angular/router": "^15.0.0",
    "zone.js": "^0.13.3"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "^15.0.0",
    "@angular/compiler-cli": "^15.0.0",
  }

Answer 4

I have downgraded one by one all packages from file package.json. The version 15 is now working. I have found and followed up this link: link