Compare OpenAPI Specs — Visual Diff Online

Before shipping a new API version, it helps to know exactly what changed: which endpoints were added or removed, which parameters became required, which response schemas shifted. SpecViewer includes a built-in visual diff tool for exactly this — load two OpenAPI or Swagger specs side-by-side and see the differences highlighted.

What the diff tool shows

• Added and removed paths and operations.
• Parameter changes, including new required fields.
• Schema/model differences between two versions of the same spec.
• A summary view plus a detailed, expandable breakdown.

Common use cases

• API versioning review — confirm a new spec version is backward-compatible before release.
• Catching breaking changes — spot a removed field or endpoint before consumers do.
• Reviewing a teammate's spec changes — compare a draft against the current production spec.

How to compare two specs

1. Open specviewer.app and add both specs (paste YAML or import files).
2. Select the two specs you want to compare.
3. Click Compare to open the visual diff drawer.