npx

npx is pre-Bundled with npm since version 5.2.0.

npx can run a locally installed package easily:

npx your-package

However, the major advantage of npx is the ability to execute a package that wasn’t previously installed:

npx cowsay wow	

The cowsay package will be deleted once the project is started. So, when we want to try something new without installing it permanently, using npx is a good choice.

npx also can be used to test different versions of packages. For example, if we want to test the upcoming version of create-react-app, we can just:

npm v create-react-app
# dist-tags:
# canary: 3.3.0-next.38  latest: 5.0.1          next: 5.1.0-next.14
 
npx create-react-app@next sandbox

npx will temporarily install the next version of create-react-app, and then it’ll execute to scaffold the app and install its dependencies.

Once installed, we can navigate to the app like this:

cd sandbox

and then start it:

npm start

References §

• npm vs npx — What’s the Difference?
• npx 是什麼? 跟 npm 差在哪?