New

OpenAPI Spec Validator

Runs in browser

Validate OpenAPI 3.x and Swagger 2.0 specs in YAML or JSON. See valid/invalid status, errors, endpoint and schema counts — all in the browser.

OpenAPI Spec Validator tool

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Files never leave your browser.

Drag and drop a file here, or tap to select

Validation

Enter an OpenAPI document to validate.

How to use

  1. Paste spec

    Load OpenAPI YAML or JSON in the left panel or drop a file.

  2. Review results

    Valid specs show a green badge and stats; invalid specs list parser or schema errors.

  3. Chain output

    Send a valid document to YAML→JSON or JSON formatter from the tool chain menu.

Examples

  • Minimal OpenAPI 3

    Default sample.

    Output
    Valid — 1 path, 1 operation.

Frequently asked questions

Does validation call remote APIs?
No — @apidevtools/swagger-parser runs locally in your browser for this tool.
Are warnings always shown?
The parser reports spec errors; additional style warnings may be empty when none apply.

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