What's the difference between tilde(~) and caret(^) in package.json?

Question

After I upgraded to latest stable node and npm, I tried npm install moment --save. It saves the entry in the package.json

Answer 1

npm allows installing newer version of a package than the one specified. Using tilde (~) gives you bug fix releases and caret (^) gives you backwards-compatible new functionality as well.

The problem is old versions usually don't receive bug fixes that much, so npm uses caret (^) as the default for --save.

According to: "Semver explained - why there's a caret (^) in my package.json?".

Note that the rules apply to versions above 1.0.0 and not every project follows semantic versioning. For versions 0.x.x the caret allows only patch updates, i.e., it behaves the same as the tilde. See "Caret Ranges"

Here's a visual explanation of the concepts:

Source: "Semantic Versioning Cheatsheet".