How to Convert yarn.lock and package-lock.json Files to Each Other

When using Node package managers npm or yarn, package-lock.json or yarn.lock files are automatically generated. However, if you want to convert yarn.lock to package-lock.json or vice versa, what should you do?

[Note] What is the reason for the change?
The reason for the change is that there were many peer dependency version issues when using npm, and it seemed more convenient to switch to yarn. To install yarn, I used the following method by converting package-lock.json to yarn.lock. Now let's find out how to do it.

! How to Convert yarn.lock and package-lock.json Files to Each Other

A simple way is to install synp and use it on the command line. The installation and usage are very simple. First, install synp:

Install it globally to use the CLI command. Now you can convert to the desired lock type. Perform each of the following as shown below. Note that if the file already exists, an error will occur, so you should delete it or rename it.


@ Generate yarn.lock from package.json
The source file is package-lock.json and yarn.lock file will be created.

I checked and found that the yarn.lock file was newly created. It is about 600kb in size, and it turns out that the lock file is larger than I thought. The package-lock.lock file is even larger at 1.6M. Next, let's try to generate package.json from yarn.lock. Only the source file needs to be changed.


@ Generate package.json from yarn.lock
This time, the source file is yarn.lock, and package-lock.json file will be created.

Using this method, it is advantageous that both yarn and npm can be converted to the desired lock file.

So far, we have briefly learned about how to convert between yarn and npm lock files.