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Generate plain Java model classes from a JSON object or object array. Download a ZIP with separate class files, then review inferred types and add your serializer mapping.
Open toolOpenAPI Validator
Check a local Swagger 2.0, OpenAPI 3.0 or OpenAPI 3.1 document for schema errors and broken internal references. Read the reported paths without querying your API.
Free to useNo sign-upRuns in your browser
Enter your details
Enter the inputs, then select Validate OpenAPI.
Your result
Enter your details
Result will appear here
How OpenAPI Validator works
Validate JSON or YAML against the bundled official specification schema and check internal references.
Processing uses bundled libraries in this browser. The result table shows the supported checks; it does not query another service.
How to validate OpenAPI
Start with the supported input, then check the generated result.
Enter the source details
Use OpenAPI JSON or YAML. The form starts with an example you can replace.
Input and settings
Check the input settings
Read the supported input format and size limits before submitting.
Tool result
Read the result table
Read each reported path or recorded value. A clean table only covers the checks described on this page.
Review the details
When to use OpenAPI Validator
These workflows use the formats and behavior supported by this implementation.
Check a spec before review
Check a JSON or YAML specification before sending it for review. Issue rows identify the document paths that need attention.
Find a broken local reference
Find a missing local schema reference without sending the document to another service. External references remain unresolved.
Review a version change
Use the declared specification version to select the appropriate structural schema. A valid document still needs endpoint and behavior tests.
What the check result contains
Keep the output format and conversion policy in view.
Schema errors for Swagger 2.0, OpenAPI 3.0 or OpenAPI 3.1. Validate JSON or YAML against the bundled official specification schema and check internal references.
Compare the result with the original before replacing a source file. Conversion limits are listed below.
Supported input and limits
Check these conditions before relying on the result.
No remote references are fetched. External references are reported as unresolved. Structural validation does not test endpoints, authentication or API behavior.
Input and results are not stored after leaving or reloading. Keep the original and download any output you need.
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OpenAPI Validator: common questions
Answers about using OpenAPI Validator and understanding its results.
What does this tool produce?
It produces schema errors for Swagger 2.0, OpenAPI 3.0 or OpenAPI 3.1. No remote references are fetched. External references are reported as unresolved. Structural validation does not test endpoints, authentication or API behavior.
Is my input uploaded?
Processing runs in this browser with local bundled libraries. No input is sent to a conversion server. Download your result before leaving the page.