Semantic Versioning and Changelogs
Learn the principles of semantic versioning and how to maintain effective changelogs for your projects.
What is Semantic Versioning?
Semantic Versioning (often abbreviated as SemVer) is a versioning system that helps developers convey meaning about the underlying changes in a software release.
A semantic version number is structured as:
- MAJOR version when you make incompatible API changes
- MINOR version when you add functionality in a backward-compatible manner
- PATCH version when you make backward-compatible bug fixes
Example: SemVer
- 1 → Major version
- 4 → Minor version (new features added)
- 2 → Patch version (bug fixes only)
Example: Pre-release and Build Metadata
SemVer also supports optional metadata:
alpha
= pre-release label+001
= build metadata
Why Use Semantic Versioning?
- Sets clear expectations for users
- Improves dependency management in package ecosystems
- Communicates impact and urgency of updates
- Prevents accidental breakage in integrations
What is a Changelog?
A changelog is a file (commonly named CHANGELOG.md
) that records notable changes in a project. It's intended for developers and users to quickly see what’s new, fixed, or changed.
Why Keep a Changelog?
- Transparency: Users and contributors can see what’s changed and why.
- Collaboration: Helps teams coordinate changes and understand the evolution of the codebase.
- User Communication: Provides clear documentation for version upgrades, including breaking changes or new features.
- Debugging: When bugs appear, changelogs offer clues on when regressions may have been introduced.
What Makes a Good Changelog?
A good changelog is:
- Human-readable: Avoid raw Git commit logs. Summarize meaningfully.
- Structured: Group changes into categories like
Added
,Changed
,Deprecated
,Fixed
,Removed
, andSecurity
. - Consistent: Use the same format for every release.
- Versioned: Clearly associate entries with specific version numbers.
- Dated: Include the release date for each version.
Example: Changelog (Using Keep a Changelog Format)
Best Practices for Changelogs
- Use Keep a Changelog format.
- Always tag your versions in Git:
- Keep a CHANGELOG.md file at the root of your project.
Final Thoughts
Semantic versioning and well-maintained changelogs enhance collaboration, reliability, and trust. They help your software tell a clear story — one version at a time.