---
title: Semantic versioning for software libraries
description: Adopt best practices in your software libraries using the semantic versioning specification.
url: https://www.felixsanz.dev/articles/semantic-versioning-for-software-libraries
language: en
published: 2014-08-18
updated: 2016-07-02
tags:
  - development
alternate-es: https://www.felixsanz.dev/es/articulos/versionamiento-semantico-para-librerias-de-software
---

# Semantic versioning for software libraries

## Introduction

When you set out to create an application or software library, one of the first things to do is to **assign a version number**. But... when do we reach version 1.0? It doesn't make sense if we are going to make up the numbers.

Still, this shouldn't be a problem when no one else is affected if you have given your software version 1.0 or 0.1, but nowadays we have great pieces of software called **package managers**.

For example, [npm](https://www.npmjs.org) (package manager for Node.js) is a system by which we can install libraries, which in turn **depend on others**. These packages may need a specific version, higher or lower than other packages they depend on, and if each owner gives his project the version numbers he wants, **it would be chaos**.

## Semantic versioning

Faced with such a need, **semantic versioning** was born, a project that aims to solve this dilemma through **convention** and **good practices**.

*[Diagram]*

Broadly speaking, **SemVer** proposes to use **X.Y.Z** for versioning.

-   **X**: *major* version. Used when changes are introduced that are not compatible with previous versions.
-   **Y**: *minor* version. Used when new functionalities are added and compatibility is not broken.
-   **Z**: *patch* version. Bug fixes compatible with previous versions.

It is also allowed to specify a **version name**, for example:

-   1.0.1-alpha
-   1.0.1-beta
-   1.0.1-sausages

This means that, for example, if our application uses the "foobar" library, **we could update that library without risk** as long as the change is a *minor* or a *patch*. Very convenient, right?

You can check the rest of the specification as well as a list of frequently asked questions at [semver.org](https://semver.org).