API contracts & developer workflows
OpenAPI Developer Tools
Inspect a saved API contract, prepare readable examples, or review changes before a release. Choose a tool by the task you need to complete. This collection also includes HTTP header helpers for preparing requests.
Processing runs in your browser without uploading your specification. Read the privacy and reference handling notes on each tool page for its exact scope.
Validate, format & convert
OpenAPI Validator
Check OpenAPI documents for valid YAML or JSON and essential structure.
OpenAPI Formatter
Format OpenAPI documents as readable JSON or YAML.
OpenAPI YAML to JSON
Convert an OpenAPI YAML document into formatted JSON.
OpenAPI JSON to YAML
Convert an OpenAPI JSON document into readable YAML.
Compare & migrate
OpenAPI Diff
Compare endpoint and operation changes between two OpenAPI documents.
OpenAPI Breaking Change Checker
Flag removed operations and newly required request fields between API specs.
OpenAPI Schema Diff
Compare named component schemas between two OpenAPI documents.
OpenAPI Migration Report
Summarize endpoint, component schema, version, and server URL changes between two specifications.
Inspect API documents
OpenAPI Endpoint Extractor
List methods, paths, summaries, and operation IDs from an OpenAPI document.
OpenAPI Schema Viewer
Inspect component schemas, fields, required values, and references.
OpenAPI Security Checker
Review declared security requirements, unused schemes, and HTTP server URLs.
OpenAPI Parameter Viewer
List path and operation parameters with location, required state, and basic type.
OpenAPI Response Viewer
Summarize response status codes, descriptions, and content types per operation.
OpenAPI Operation ID Checker
Find missing or duplicate operationId values across OpenAPI paths.
OpenAPI Deprecated API Finder
Find operations, parameters, and component schemas marked deprecated.
OpenAPI Version Checker
Identify an OpenAPI version and report whether this toolset checks its version family.
OpenAPI Tag Index
Group operations by their OpenAPI tags and show each tag's description.
Generate examples & requests
OpenAPI cURL Generator
Generate a cURL example for a selected method and path in an OpenAPI spec.
HTTP Header Builder
Validate and normalize an HTTP header block for a request.
OpenAPI Example Generator
Create a sample JSON value from a named component schema and local references.
A practical contract review
- Format a saved specification and check its basic structure before comparing versions.
- Compare the released document with the proposed document, then inspect operation and component schema changes separately.
- Review referenced definitions and run representative consumer tests before deciding whether a release is compatible.
What these tools do not establish
Parsing or a successful check is not proof of complete OpenAPI compliance, backward compatibility, or secure runtime behavior. Individual pages describe their version checks and limitations. The example generator follows selected local schema references; it does not resolve every reference or constraint.
Related developer guides
- How to Detect Breaking Changes in OpenAPI — Compare API contracts, investigate removed operations and required inputs, and understand the limits of a local OpenAPI diff.