Detect OpenAPI breaking changes before release
Compare two OpenAPI specs locally and flag breaking changes such as removed paths, removed methods, required fields, or changed response schemas.
Open the tool, then paste the sample input below. Everything runs locally in your browser.
The problem
A small OpenAPI edit can break clients when a path disappears, a request field becomes required, or a response type changes. Diffing the old and new specs before release gives reviewers a focused checklist.
Sample input
Old: GET /users/{id} returns 200 User
New: GET /users/{id} removed; GET /members/{id} addedExpected output
Breaking: removed operation GET /users/{id}
Non-breaking: added operation GET /members/{id}How to do it
- Paste the current OpenAPI spec.
- Paste the proposed OpenAPI spec.
- Run the analyzer.
- Review breaking and non-breaking changes separately.
- Share the summary with API reviewers.
Common mistakes
- Only checking endpoint names and missing schema changes.
- Treating added required request fields as safe.
- Ignoring removed enum values.
- Comparing formatted YAML without semantic checks.
Related tools
FAQ
What counts as an OpenAPI breaking change?
Removed paths, removed methods, stricter request requirements, and incompatible schema changes are common breaking changes.
Can added endpoints be breaking?
Usually no, but added required fields or changed behavior on existing endpoints can be breaking.
Are my OpenAPI specs uploaded?
No. The comparison runs locally in your browser.
Is my data uploaded anywhere?
No. This workflow runs locally in your browser unless you explicitly copy or share the result yourself.
This guide uses browser-local tooling. Avoid pasting production secrets unless you understand what the tool displays and shares.
Continue with adjacent browser-based tools for the same workflow.