# OpenAPITools/openapi-diff

Utility for comparing two OpenAPI specifications.

Repository: https://github.com/OpenAPITools/openapi-diff
Canonical: https://ross.abutalabs.com/products/openapi-diff
Language: Java
License: Apache-2.0
License Family: permissive
Topics: openapi, openapi3, swagger, diff, api, openapi-specification, openapi-diff
Last push: 2026-08-14T08:42:27+00:00

## Health v2 (maintenance only)
Score: 87/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 97, release rhythm 68, longevity 100
- inputs: {"age_days": 3187, "days_push": 19, "days_rel": 219, "gap_med": 22, "n_releases_24m": 8}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1095, forks 191 (observed 2026-08-28T04:03:34.128669+00:00)

## What it is
A Java-based utility that compares two OpenAPI 3.x specifications and reports the differences. It can render diffs as HTML, Markdown, Asciidoc, or JSON, and is available as a CLI, Maven library, and Docker image.

## Use cases
- compare two openapi specs for breaking changes
- detect backward-incompatible api changes in ci
- generate a changelog of api differences as markdown
- diff swagger v3 specifications
- fail a build when api contract changes
- check if a new api version is backward compatible

## When to choose
- you need to detect breaking changes between OpenAPI 3.x versions in CI/CD
- you want diff output in HTML, Markdown, Asciidoc, or JSON
- you need a Java library for programmatic OpenAPI comparison
- you want a ready-made CLI or Docker image for spec diffing

## When to avoid
- you need to diff OpenAPI 2.0 (Swagger) specs only
- you need a general-purpose JSON or YAML diff tool
- you work outside the JVM ecosystem and don't want a Java-based tool

## Facets
- artifact type: cli-tool
- maturity: active
- function: developer-tools, api-framework, documentation
- domain: apis, developer-tools
- platform: cli, jvm
- tags: openapi, swagger, api-diff, backward-compatibility, spec-comparison, api-documentation, docker, macos

## Member repositories
- OpenAPITools/openapi-diff (main) score 87

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:34.128669+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:47:13.930171+00:00, confidence not recorded.
  - readme: https://github.com/OpenAPITools/openapi-diff (fetched 2026-08-28T04:03:34.128669+00:00, sha c6a8d28ee74b)
- Data as of 2026-08-30T08:39:29.467469+00:00.