OpenAPI JSON to YAML Converter

Convert OpenAPI/Swagger JSON to YAML entirely in your browser. Fast, free, and private.

Input JSON
Output YAML

All conversions happen locally in your browser. No files are uploaded and no network requests are made. Code is open source.

About OpenAPI JSON to YAML Converter

A fast, free, browser-based OpenAPI JSON to YAML converter for API specifications. Convert OpenAPI and Swagger definitions between JSON and YAML with zero setup. The tool works seamlessly with OpenAPI 3.0, OpenAPI 3.1, and Swagger 2.0 (OpenAPI 2.0).

Key Features

  • Instant conversion: Transform Swagger/OpenAPI JSON ↔ YAML in real time
  • Flexible input: Paste content, upload files, or fetch from a URL
  • Standards support: Compatible with OpenAPI 3.0, 3.1, and Swagger 2.0
  • Smart detection: Automatically identifies JSON or YAML input
  • Private by design: All processing runs locally in your browser
  • Export ready: Copy to clipboard or download the converted spec

How to Convert OpenAPI JSON to YAML

  1. Add your spec: Paste JSON, upload a .json file, or provide a URL
  2. View the result: Conversion to YAML happens instantly
  3. Save or share: Copy the output or download the YAML file

Supported Formats

The converter supports the most widely used API specification formats:

  • OpenAPI 3.1 — Modern OAS with full JSON Schema alignment
  • OpenAPI 3.0 — The widely adopted successor to Swagger 2.0
  • Swagger 2.0 — Legacy (OpenAPI 2.0) specifications

Why Convert Between JSON and YAML?

JSON is compact and broadly supported across tooling, CI/CD, and SDK generators. YAML is concise and human-readable, ideal for authoring and reviewing API definitions. Teams often convert to:

  • Integrate with documentation, testing, and gateway platforms
  • Collaborate across teams with different format preferences
  • Improve readability for code reviews and version control
  • Meet pipeline or validator requirements for a specific format

Common Use Cases

API Documentation

Convert your OpenAPI files to the format required by tools such as Swagger UI, Redoc, or Postman.

API Gateway Configuration

Match the input format expected by popular API gateways by converting between JSON and YAML.

Version Control

Prefer YAML for clearer diffs in Git, or convert to JSON for tooling that requires it.

API Testing

Provide your test frameworks and validators with specs in their preferred format.

Frequently Asked Questions

Is this OpenAPI converter free to use?

Yes. The converter is completely free—no registration or payment needed.

Does the converter support Swagger 2.0?

Yes. It supports Swagger 2.0 (OpenAPI 2.0) as well as OpenAPI 3.0 and 3.1.

Is my API specification data secure?

Absolutely. Conversion runs locally in your browser—your files are not uploaded to a server.

Can I convert large OpenAPI files?

Yes. The in-browser approach handles large specifications efficiently, without external upload limits.

What's the difference between OpenAPI and Swagger?

Swagger was renamed to the OpenAPI Specification in 2016; "Swagger" commonly refers to the tooling ecosystem, while "OpenAPI" refers to the specification itself.

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