Enter a JSON object that represents your data structure.
Review generated schema
See the JSON Schema automatically generated from your sample.
Copy the schema
Click Copy to use the schema for OpenAI function calling or validation.
Frequently Asked Questions
Is the JSON Schema Builder free?
Yes, the JSON Schema Builder is completely free with no limitations. Create as many schemas as you need for OpenAI structured outputs or API validation without registration.
Is my schema data private?
Yes, all schema building happens locally in your browser. Your schemas and sample data are never sent to any server, keeping your API structures confidential.
What is JSON Schema used for?
JSON Schema defines the structure of JSON data for validation, documentation, and code generation. It is particularly useful for OpenAI structured outputs, API request/response validation, and form generation.
Does this tool support OpenAI structured outputs?
Yes, the tool generates schemas compatible with OpenAI structured outputs. You can define response formats that ensure AI models return data in exactly the structure your application expects.