json-to-json-schema-generator
JSON Schema Generator
Transform your JSON data into complete Draft 2020-12 validation schemas.
Guide & Explanations
JSON Schema Generator: Create Validation Schemas Instantly
In modern API and application development, data validation is crucial. The JSON Schema standard (Draft 2020-12) is the leading tool for contractually defining the structure of your JSON objects. Our tool allows you to generate this schema automatically from a simple data example.
Why use our generator?
- Intelligent Type Inference: The tool not only detects objects and arrays but also distinguishes between
numberandinteger. - Automatic Format Detection: If your strings look like emails, ISO dates, IP addresses, or URLs, the tool automatically adds the appropriate
formatconstraint. - Object Array Merging: When you provide an array containing several slightly different objects, the tool merges their properties to create a global schema that accepts all valid variants.
- Customization Options: Choose to make all keys mandatory (
required), include real value examples in the schema, or prepare description fields for your Swagger/OpenAPI documentation.
How does it work?
Simply copy your JSON object into the left-hand area. The validation schema is instantly displayed on the right. You can then copy it into your project or download it as a .json file. All processing is done locally in your browser for total privacy.
Frequently Asked Questions
Q: Is json-to-json-schema-generator free to use?
R: Yes, the json-to-json-schema-generator utility is 100% free. All tools on Dolf.in are accessible at no cost and without intrusive ads.
Q: Is my data secure?
R: Absolutely. Dolf.in uses a 'Serverless' approach: your data is processed locally in your browser and is never sent to our servers.
Q: Do I need to install any software?
R: No, no download or installation is required. Everything works directly in your web browser.
Q: What is JSON Schema and why generate one?
R: JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. Generating a schema from an example allows you to contractually define the expected structure of an API, making it easier to validate incoming data, generate technical documentation, and automate typing in many programming languages.
Q: How does the tool handle arrays of objects?
R: If you provide an array containing multiple objects, our engine performs a 'union' merge of properties. It analyzes each object to collect all possible keys, ensuring that the generated schema covers all cases present in your data sample.
Q: Which formats are automatically detected?
R: The tool analyzes strings to identify specific patterns. It automatically detects standardized formats: ISO 8601 Dates, Email addresses, IPv4/IPv6 addresses, and URLs. This information is added via the 'format' key for stricter validation.