OpenAPI / Swagger Editor
API StudioEdit, validate, and preview OpenAPI 3.0/3.1 & Swagger 2.0 specifications in YAML or JSON with live interactive documentation.
PetStore Nexus API
Welcome to the **PetStore Nexus API**! This interactive documentation allows you to test endpoints, inspect request bodies, generate `curl` commands, and validate payloads client-side.
Complete Guide to OpenAPI & Swagger API Specifications
Learn the differences between OpenAPI 3.0, 3.1, and Swagger 2.0, how to write clean REST API contracts, and how live documentation accelerates API design.
The OpenAPI Specification (OAS), originally known as Swagger, is the broadly adopted industry standard for defining RESTful APIs. An OpenAPI document describes the entire API surface: available endpoints (e.g. /users, /orders), supported HTTP operations (GET, POST, PUT, DELETE, PATCH), input parameters (path, query, header, cookie), request body payloads, response status codes, and reusable component schemas.
Writing an accurate OpenAPI specification allows development teams to practice API-first design: generate mock servers before backend code is written, produce client SDKs in dozens of programming languages with OpenAPI Generator, configure API gateways, and publish interactive documentation for partner integrations.
OpenAPI 3.0 vs. OpenAPI 3.1 vs. Swagger 2.0
While Swagger 2.0 relied on host, basePath, and definitions with in: body parameters, OpenAPI 3.0introduced flexible multi-server configurations (servers), granularrequestBody content types, and consolidated components.schemas. OpenAPI 3.1 further harmonized with full JSON Schema Draft 2020-12 compatibility and introduced native webhooks support. JSON Studio seamlessly validates and renders all three specification standards.
How to Use This Tool
Upload or Paste Specification
Paste your API specification in either YAML or JSON, or click Upload Spec to load an existing .yaml, .yml, .ymal, or .json file from your system.
Bi-Directional Format Conversion
Seamlessly convert between YAML and JSON with one click. Monaco Editor automatically adjusts syntax coloring and brace matching.
Real-Time Syntax & Ref Linting
Review the diagnostics banner for structural errors, missing required info fields, path formatting issues, or broken schema $ref references.
Interactive Swagger Documentation
Inspect endpoints grouped by tag, filter by HTTP method, review parameter tables, and examine request/response schemas.
Live cURL Command Generation
Enter parameter values and request bodies to automatically generate an executable, copyable cURL terminal command for instant API testing.
Key Features & Capabilities
Dual Split-Screen Workspace
Code on the left with instant, synchronized Swagger UI interactive documentation on the right. Toggle between Split, Editor Only, and Preview Only.
Automatic Format Detection
Smart detection recognizes JSON or YAML instantly on upload or paste, eliminating manual configuration.
Component Schema Inspector
Explore defined data models (#/components/schemas) with property types, required constraints, and example payloads.
100% Client-Side Privacy
Draft proprietary internal API specifications safely. Zero spec documents or tokens ever leave your local machine.
Frequently Asked Questions
What is the difference between OpenAPI and Swagger?
Can I convert my Swagger 2.0 or OpenAPI YAML spec to JSON?
How does the live cURL generator work?
Does the validator check broken $ref references?
Privacy & Security Guarantee
All data processing, AST syntax repairs, and cryptographic operations happen 100% locally inside your browser using native JavaScript and WebAssembly. No inputs, keys, or file payloads are ever transmitted to or stored on remote servers.