API Tools
Design, validate, and test your APIs with visual editors and real-time feedback.
JSON Schema Validator
Validate JSON data against a JSON Schema definition. Supports all drafts (4, 6, 7, 2019-09, 2020-12). Human-readable error messages with fix suggestions.
JSON to Schema Generator
Automatically generate a JSON Schema from any JSON example. Detects types, formats, nested objects, and arrays. Refine with an interactive editor.
OpenAPI Editor
Build OpenAPI 3.x specifications with a visual editor. See your API documentation rendered in real-time as you define endpoints.
API Validator
Validate API responses against OpenAPI specs or JSON Schema. Paste a response and check it matches your contract.
Mock Data Generator
Generate realistic mock data from any JSON Schema or OpenAPI component schema. Locale-aware fake data for names, emails, addresses, and more. Seeded output, CSV export.
Breaking Change Detector
Compare two versions of a JSON Schema or OpenAPI spec to detect breaking changes, warnings, and safe modifications. Generate changelogs for API releases.
Mock Server
Generate mock API responses from your OpenAPI spec. Get realistic sample data for testing your frontend without a backend.