Why does is-number have so many npm downloads?
is-number got about 225M downloads last week. Probably very few of them came from someone choosing it.
Follow the dependency trail
Each package below requires the one above it, and their weekly downloads on the matching versions line up within about 30%:
- is-number 7.0.0 225M a week
- to-regex-range 5.0.1 211M a week
- fill-range 7.1.1 217M a week
- braces 3.0.3 218M a week
Installing any package at the end of that trail fetches every package before it. So a build tool used by millions of projects adds a download to each small helper underneath it, on every clean install and every CI run.
Are those real installs?
Yes. The tarball really is fetched and installed, so filtering out mirrors and crawlers barely changes a number this size. What it doesn't tell you is that anyone decided to use the package. For a package like this, a download count mostly measures how popular its dependents are.
How do I see why a package is in my project?
Run npm explain is-number. It prints the chain of dependencies that brought the package in.
How do you know?
You can't know exactly, because npm doesn't record who requested a download. We compare weekly per-version counts: when one package requires another, and the versions in question get nearly the same downloads, that package probably explains them. Where several big packages share a dependency, the shares overlap and can't be told apart, so we stop there. Package pages show a trail like this for the 16 packages where we could follow one.