API & Schema Tools
Format, validate, and convert OpenAPI, JSON Schema, and GraphQL SDL in your browser — seven tools, nothing uploaded.
- Tighten OpenAPI and JSON Schema specs before CI or gateway import.
- Validate GraphQL SDL alongside REST contract work.
- Convert between OpenAPI and JSON Schema without leaving the browser.
Format OpenAPI
Pretty-print OpenAPI JSON or YAML with 2 or 4 space indent.
Validate OpenAPI
Validate OpenAPI 3.0–3.2 schema conformance in your browser.
Lint OpenAPI
Lint OpenAPI path operations with a Spectral-style rule subset.
JSON Schema to OpenAPI
Convert JSON Schema to a minimal OpenAPI 3.0 document.
OpenAPI to JSON Schema
Extract OpenAPI components.schemas into JSON Schema $defs.
JSON Schema Validator
Validate JSON data against Draft-07 or 2020-12 schemas.
Validate GraphQL
Validate GraphQL schema SDL with buildSchema in your browser.
Guides
OpenAPI: Lint, Format and Structure a Maintainable API
operationId, tags, error responses: rules that prevent spec debt on OpenAPI files.
Validate OpenAPI 3 / Swagger Specs Online Before CI
Schema errors, broken $ref, missing responses: validate your OpenAPI 3.0–3.2 API contract in the browser.
Optimize REST API Performance with JSON Minification
Speed up your REST APIs by optimizing JSON payloads. Minification, compression, pagination and best practices for ultra-fast APIs.
JSON Minification Guide — APIs, Config Files & Express
Minify JSON for APIs and config files: JavaScript, Python and jq examples, Express middleware, and when minification beats pretty-printing in production.