Convert OpenAPI and Swagger API specifications between YAML and JSON formats instantly. Free, fast, and secure browser-based tool supporting OpenAPI 3.0, OpenAPI 3.1, and Swagger 2.0.
Convert your OpenAPI YAML specifications to JSON format. Perfect for tools that require JSON input or when you need a more compact format.
Convert your OpenAPI JSON specifications to YAML format. Ideal for better readability, clearer diffs in version control, and easier editing.
All conversions happen locally in your browser. Your API specifications never leave your device—no uploads, no tracking, no data collection.
Instant conversion with real-time syntax validation. No waiting for server processing—see results immediately as you paste or load your files.
Supports OpenAPI 3.1, OpenAPI 3.0, and Swagger 2.0 specifications. Compatible with all major API documentation and gateway tools.
Paste content directly, upload local files (.yaml, .yml, .json), or fetch specifications from any URL. Flexible input for any workflow.
Copy converted output to clipboard with one click or download as properly formatted .json or .yaml files. Ready to use in your projects.
No registration, no limits, no hidden costs. Use the converter as many times as you need for personal or commercial projects.
Convert specifications to match the format required by Swagger UI, Redoc, Postman, Stoplight, or any other API documentation tool.
Prepare OpenAPI specs for deployment pipelines, API gateways (Kong, AWS API Gateway, Azure), or automated testing frameworks that require specific formats.
Convert to YAML for cleaner Git diffs and better code reviews, or to JSON for compact storage and faster parsing in production environments.
Convert specs for API testing tools, schema validators, mock servers, and contract testing frameworks that work with specific formats.
OpenAPI (formerly Swagger) is a standard specification format for describing REST APIs. Different tools and workflows prefer either YAML (more readable, better for editing) or JSON (more compact, faster to parse). Our converter lets you switch between formats instantly.
Yes! This OpenAPI converter is completely free with no limitations. No registration required, no file size limits, no usage caps. Convert as many specifications as you need.
Absolutely. All conversion happens in your browser using client-side JavaScript. Your files never leave your computer—no uploads to any server, no network requests, no data storage. Your API specifications remain completely private.
The converter fully supports OpenAPI 3.1, OpenAPI 3.0, and Swagger 2.0 (OpenAPI 2.0) specifications. It works with any valid YAML or JSON OpenAPI document.
Yes. Since processing happens locally in your browser, there are no server-side file size limits. The converter handles large, complex API specifications efficiently.
The converter includes built-in syntax validation. If your input contains errors, you'll see a helpful error message indicating what needs to be fixed before conversion can complete.
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Choose your conversion direction and get started instantly. No sign-up required.