OpenAPI diff tool

Compare OpenAPI changes before they reach production.

API Contract Guard gives teams a free OpenAPI diff tool for quick checks and a GitHub App for enforcing the same compatibility result on every pull request.

01

Paste two specifications

Compare a baseline OpenAPI document with a proposed JSON or YAML version and see the removed paths, responses, parameters and schemas.

02

Review the breaking changes

The report focuses on changes that can break existing API consumers, rather than burying the decision inside a generic text diff.

03

Move the check into GitHub

When the manual check becomes part of your release process, install the GitHub App and make the compatibility result a required pull-request status.

AUTOMATE THE CHECK

Protect every pull request automatically

Install the GitHub App, choose a repository and get a clear pass or fail status whenever its OpenAPI contract changes.

Start free · first month £1
COMMON QUESTIONS

Frequently asked questions

Can I use it without installing anything?

Yes. The browser checker can compare OpenAPI YAML or JSON files without a GitHub installation.

What does the automated version do?

The GitHub App watches pull requests, compares changed OpenAPI files against the base branch and publishes a native GitHub Check.

Does API Contract Guard store my OpenAPI files?

OpenAPI file contents are fetched for analysis and are not stored as long-term product records.