Stability Index

Stability Indexes

1. When you want to read node.js documentation about a specific feature, node.js provide an easy information about the current status of this feature. The stability index. 

This is a number between 0, 1 and 2, that symbolizes how mature the given node.js module is. This is only for the core node.js modules, and not the ones that we download and install externally from NPM (we will talk about the difference later). What do these numbers symbolize then?

0 means deprecated feature and it's usage should be avoided.

1 means experimental. Not fully stable but latest node.js versions should run with it.

2 means stable and it's the safest index to go with.

Additionally, on history section of each core module you can see, when the history of the module's status, the dates the module was included to node.js and the date it became standard (if not yet in experimental) as the picture shows. 

Check node.js docs for more here.