Does this support YAML specs?

Currently JSON only. Use our YAML to JSON converter to transform your spec first, then paste the JSON here.

Which OpenAPI versions are supported?

OpenAPI 3.0.x, 3.1.x, and Swagger 2.0 are all supported for structural validation.

Is my API spec sent to a server?

No. All validation happens 100% client-side in your browser. Your spec never leaves your device.

How thorough is the validation?

We check required fields, path structure, parameter definitions, response codes, security schemes, and best practices. For full OAS compliance, consider also using official tooling.

📋

OpenAPI / Swagger Validator

Validate and inspect API specifications

← All Tools

OpenAPI / Swagger Spec (JSON)132 lines

{
  "openapi": "3.0.3",
  "info": {
    "title": "Pet Store API",
    "description": "A sample API for a pet store",
    "version": "1.0.0",
    "contact": {
      "name": "API Support",
      "email": "support@example.com"
    },
    "license": {
      "name": "MIT"
    }
  },
  "servers": [
    {
      "url": "https://api.petstore.example.com/v1",
      "description": "Production"
    }
  ],
  "paths": {
    "/pets": {
      "get": {
        "operationId": "listPets",
        "summary": "List all pets",
        "tags": ["pets"],
        "parameters": [
          {
            "name": "limit",
            "in": "query",
            "required": false,
            "schema": { "type": "integer", "maximum": 100 }
          }
        ],
        "responses": {
          "200": {
            "description": "A list of pets",
            "content": {
              "application/json": {
                "schema": {
                  "type": "array",
                  "items": { "$ref": "#/components/schemas/Pet" }
                }
              }
            }
          }
        }
      },
      "post": {
        "operationId": "createPet",
        "summary": "Create a pet",
        "tags": ["pets"],
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": { "$ref": "#/components/schemas/NewPet" }
            }
          }
        },
        "responses": {
          "201": {
            "description": "Pet created",
            "content": {
              "application/json": {
                "schema": { "$ref": "#/components/schemas/Pet" }
              }
            }
          }
        },
        "security": [{ "bearerAuth": [] }]
      }
    },
    "/pets/{petId}": {
      "get": {
        "operationId": "getPet",
        "summary": "Get a pet by ID",
        "tags": ["pets"],
        "parameters": [
          {
            "name": "petId",
            "in": "path",
            "required": true,
            "schema": { "type": "string" }
          }
        ],
        "responses": {
          "200": {
            "description": "A pet",
            "content": {
              "application/json": {
                "schema": { "$ref": "#/components/schemas/Pet" }
              }
            }
          },
          "404": {
            "description": "Pet not found"
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "Pet": {
        "type": "object",
        "required": ["id", "name"],
        "properties": {
          "id": { "type": "integer", "format": "int64" },
          "name": { "type": "string" },
          "tag": { "type": "string" },
          "status": { "type": "string", "enum": ["available", "pending", "sold"] }
        }
      },
      "NewPet": {
        "type": "object",
        "required": ["name"],
        "properties": {
          "name": { "type": "string" },
          "tag": { "type": "string" }
        }
      }
    },
    "securitySchemes": {
      "bearerAuth": {
        "type": "http",
        "scheme": "bearer",
        "bearerFormat": "JWT"
      }
    }
  }
}

Related Tools

devtools

1 / 12

📐JSON Schema 📡cURL Builder 🔌Mock API 🏷️Meta Tags Generator 🌐HTTP Codes 📆Cron 🌐CIDR #Hash

← View all devtools tools Browse all categories

Showing 8 of 94 related tools

📖

About OpenAPI Validator

Validate your OpenAPI 3.x or Swagger 2.0 specifications directly in your browser. Get instant feedback on errors, warnings, and best practice suggestions. Browse endpoints, schemas, and security configurations at a glance.

Quick Start Guide

1
Paste your spec
Paste your OpenAPI/Swagger JSON specification
2
Click Validate
Get instant validation with errors and warnings
3
Browse endpoints
View all API endpoints with methods, paths, and tags
4
Inspect schemas
Review data models and their properties

✅

Validation

Check spec structure, required fields, and consistency

🛣️

Endpoint Viewer

Browse all paths with method badges and tags

📦

Schema Inspector

View data models and property counts

🔐

Security Review

See authentication schemes at a glance

🌐

Server Info

View configured server URLs and environments

⚠️

Best Practices

Warnings for missing descriptions, operationIds, etc.

Frequently Asked Questions

Last updated: February 7, 2026

📋

OpenAPI / Swagger Validator

Validate and inspect API specifications

← All Tools

OpenAPI / Swagger Spec (JSON)132 lines

Related Tools

devtools

1 / 12

📐JSON Schema 📡cURL Builder 🔌Mock API 🏷️Meta Tags Generator 🌐HTTP Codes 📆Cron 🌐CIDR #Hash

← View all devtools tools Browse all categories

Showing 8 of 94 related tools

📖

About OpenAPI Validator

Quick Start Guide

1
Paste your spec
Paste your OpenAPI/Swagger JSON specification
2
Click Validate
Get instant validation with errors and warnings
3
Browse endpoints
View all API endpoints with methods, paths, and tags
4
Inspect schemas
Review data models and their properties

✅

Validation

Check spec structure, required fields, and consistency

🛣️

Endpoint Viewer

Browse all paths with method badges and tags

📦

Schema Inspector

View data models and property counts

🔐

Security Review

See authentication schemes at a glance

🌐

Server Info

View configured server URLs and environments

⚠️

Best Practices

Warnings for missing descriptions, operationIds, etc.

Frequently Asked Questions

Last updated: February 7, 2026

Related Tools

About OpenAPI Validator

Quick Start Guide

Paste your spec

Click Validate

Browse endpoints

Inspect schemas

Validation

Endpoint Viewer

Schema Inspector

Security Review

Server Info

Best Practices

Frequently Asked Questions

Does this support YAML specs?

Which OpenAPI versions are supported?

Is my API spec sent to a server?

How thorough is the validation?

Related Tools

About OpenAPI Validator

Quick Start Guide

Paste your spec

Click Validate

Browse endpoints

Inspect schemas

Validation

Endpoint Viewer

Schema Inspector

Security Review

Server Info

Best Practices

Frequently Asked Questions

Does this support YAML specs?

Which OpenAPI versions are supported?

Is my API spec sent to a server?

How thorough is the validation?