Version Formats

title: Version Formats — Semantic Versioning and Date-Based Versions weight: 17 description: Learn API version formats including semantic versioning, date-based versions, and simple integer versions with trade-offs for each approach. date: 2026-06-28 lastmod: 2026-06-28 tags: [api-development, versioning]

API version formats specify how version identifiers are structured, with common approaches including simple integers, semantic versioning, and date-based versions.

## Common Formats

Simple integers (v1, v2, v3) are the most common for API versions. They are easy to understand, remember, and compare. Semantic versioning (1.0.0, 2.1.0) provides more granularity but can imply frequent changes. Date-based versions (2026-06-28, 2026Q2) indicate release timing.

## Recommendations

Use simple integers for API contract versions (v1, v2). Use semantic versioning for implementation versions internally. Use date-based versions for APIs released on a schedule.

## Common Mistakes

1. **Semantic versioning for APIs** — Frequent version bumps confuse clients.
2. **Inconsistent format** — Mixing v1, version2, and 2026-06-28.
3. **No version at all** — APIs without version identifiers.

## Practice Questions

1. What is the most common API version format?
2. Why avoid semantic versioning for public APIs?
3. When are date-based versions appropriate?

## What's Next

In the next lesson, you will learn backward compatibility.