Swagger Editor & OpenAPI 3.0 Editor
Edit OpenAPI 3.0 (and Swagger-style) JSON specs in this free online Swagger editor. Beautify documents, run basic structural checks, and keep API design work private in your browser. Convert YAML to JSON first for this MVP, then pair with the API Tester to try paths from your spec.
Runs entirely in your browser. Your data never leaves this device.
- Swagger / OpenAPI 3.0 JSON editing
- Basic structural validation
- Pretty-print OpenAPI specs
- Works offline in the browser
- No account required
How it works
- Paste an OpenAPI 3.0 JSON specification into the Swagger / OpenAPI editor.
- Run basic structural validation and pretty-print the document for easier review.
- Use alongside the API Tester to exercise paths from your OpenAPI 3.0 spec locally.
Key features
- Swagger / OpenAPI 3.0 JSON editing
- Basic structural validation
- Pretty-print OpenAPI specs
- Works offline in the browser
- No account required
FAQ
Is this a free Swagger editor online?
Yes. It is a browser-based Swagger editor and OpenAPI 3.0 editor MVP for editing JSON specs with basic checks — no account required.
Does it support OpenAPI 3.0?
Yes. Paste OpenAPI 3.0 JSON to beautify and run basic structural validation. Full schema validation is not included in this MVP.
YAML support?
This MVP focuses on JSON. Convert YAML to JSON first, then paste it into the OpenAPI editor.
Full OpenAPI validation?
Basic structural checks only — not a full OpenAPI schema validator or official Swagger Editor desktop replacement.
Can I try endpoints from my spec?
Use the API Tester tool with paths and methods from your OpenAPI 3.0 document.
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