What is the bower (and npm) version syntax?

javascript

dependency-management

semver

package-dependencies

byAnton Shumikhin·Mar 11, 2025

In bower and npm, versions follow semver, short for semantic versioning, which adheres to MAJOR.MINOR.PATCH principles. For a quick rundown:

Specific version: 1.2.3—choosing this is like ordering a pizza with a set combo of toppings; no surprises.
Caret (^): ^1.2.3 means >=1.2.3 <2.0.0, allows updates that don’t alter the first non-zero digit.
Tilde (~): ~1.2.3 means >=1.2.3 <1.3.0, permits updates for patches only.
Wildcard (* or x): 1.2.x or *— selecting this is like ordering a mix pizza; be ready for anything.
Pre-release: 1.2.3-alpha, 1.2.3-beta—These are your 'sneak-peeks' into the upcoming versions.

Your package.json could look like:

"dependencies": {
  "your-library": "^1.2.3"
  // Something like ordering pizza with your favorite toppings, you know what you're getting.
}

The above communicates your comfort level with version flexibility for dependencies.

Deciphering syntax symbols

Getting your head around dependency management is like understanding algebra; knowing the operators is fundamental. Here's a mini guide:

Greater (>), Less (<), Greater or Equal (>=), Less or Equal (<=): These operators set the bounds for acceptable versions, e.g., >1.2.3.
Hyphen Ranges (X.Y.Z - A.B.C): Specifies a range of desirable versions, e.g., 2.3.0 - 2.4.5.
Double-pipe (||): Helps define either-or situations for multiple versions, e.g., 1.0.3 || >1.5.0.

I recommend the node semver package's readme for an in-depth look at the syntax and its application in handling dependencies.

Visualising version ranges

Imagine your project to be an architecturally complex structure, the right turn or pivot can lead you to the right room (package version):

Making right choices

Implementing bower install <package>#^1.2.3 is like opting for a safe path with potential treasures; no pitfalls, only patches.
Opting for bower install <package>#~1.2.3 signifies taking a narrow alley, where the journey is secure with patches as your trophies.

Being specific vs being flexible

Decide on `bower install <package>#1.2.3 versus when you want to reach the exact room without any detours; stability over flexibility.

Playing in the range

Choose hyphen ranges or the double-pipe when you are open to visiting multiple rooms from different floors; illustrating a range of acceptable versions.