Developer tools
OpenAPI Diff Viewer
Review an API specification change before treating it as compatible.
Processed locally. Your input and output are never uploaded.
Tool overview
How OpenAPI Diff Viewer works
OpenAPI Diff Viewer parses two local JSON or YAML specifications and reports additions, removals, and value or type changes. It keeps input and output separate, runs locally, and documents boundaries instead of making unsupported guarantees.
Specification changes before release
- parses two local JSON or YAML specifications and reports additions, removals, and value or type changes. for a repeatable local workflow
- Review pasted or locally opened data before copying it
- Prepare output for a related PasteTidy tool
Compare two OpenAPI documents
- Paste the source or open a supported local file.
- Paste or open the secondary source when the comparison requires it.
- Choose the documented options and review the separate result.
- Copy or download only after checking the visible output.
Paths, references, and compatibility
- Original format: Format of the original document.
- Revised format: Format of the revised document.
Review an added endpoint
Before
Input ยท List A:
openapi: 3.0.0
info:
title: Demo
version: 1.0.0
paths:
/health:
get:
responses: {}
Input ยท List B:
openapi: 3.0.0
info:
title: Demo
version: 1.1.0
paths:
/health:
get:
responses: {}
/items:
get:
responses: {}Result
{
"changes": [
{
"path": "/info/version",
"change": "changed",
"before": "1.0.0",
"after": "1.1.0",
"beforeType": "string",
"afterType": "string"
},
{
"path": "/paths/~1items/get/responses",
"change": "added",
"after": {},
"afterType": "object"
}
],
"compatibility": "No removed paths detected; compatibility still requires domain review."
}Informational compatibility warnings
- External $ref targets are not fetched or resolved.
- Large input is bounded by the documented local worker limits.
- Input, options, and output are not sent to analytics or placed in URLs.
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Questions
OpenAPI Diff Viewer FAQ
Does OpenAPI Diff Viewer upload my input?
No. Processing stays in the current browser tab or its local Web Worker.
Is the result authoritative?
No. Review the output and the documented limitations before using it in a production workflow.