Postman to OpenAPI Converter — Spec Migration Tool
Convert Postman Collection v2.1 JSON to OpenAPI 3.0 specification format. Upload or paste your collection, and get a downloadable openapi.yaml or openapi.json with mapped paths, parameters, request bodies, and example responses.
How to Use Postman to OpenAPI Converter — Spec Migration Tool
How to Use the Postman to OpenAPI Converter
Step 1: Export Your Postman Collection
In Postman, open the collection you want to convert. Click the three-dot menu (⋯) next to the collection name and select Export. Choose Collection v2.1 format and save the JSON file.
Step 2: Upload or Paste the Collection
Choose one of two input methods:
- Upload File — drag and drop or click to upload the exported
.jsonfile (max 10 MB) - Paste JSON — copy the collection JSON and paste it directly into the text area
Step 3: Choose Output Format
Select YAML (recommended, human-readable, widely supported) or JSON as the output format for your OpenAPI 3.0 specification.
Step 4: Convert
Click Convert to OpenAPI. The tool will:
- Map every Postman request to an OpenAPI path and HTTP method
- Extract path variables (
:id→{id}) - Map query parameters and custom headers
- Map request bodies (JSON, form-data, URL-encoded)
- Import example responses if present in the collection
- Detect the server base URL automatically
- Generate unique
operationIdvalues for each endpoint - Organize endpoints by folder into OpenAPI tags
Step 5: Review and Download
Review the conversion summary (endpoint count, server URL, any warnings) and the preview of the generated spec. Click Download .yaml or Download .json to save the file. Use Copy to copy the content directly to your clipboard.
What Is Converted
| Postman Field | OpenAPI 3.0 Field |
|---|---|
| Collection name | info.title |
| Request name | summary + operationId |
| HTTP method | Path method key |
| URL path | paths key |
Path variables (:id) | parameters[in=path] |
| Query parameters | parameters[in=query] |
| Custom headers | parameters[in=header] |
| Raw JSON body | requestBody (application/json) |
| Form-data body | requestBody (multipart/form-data) |
| URL-encoded body | requestBody (application/x-www-form-urlencoded) |
| Example responses | responses with schemas |
| Folder structure | tags |
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