Free Tools

API Developer Tools

Free tools for API developers. No sign-up required. Powered by SchemaWatch.

OpenAPI Validator

Validate any OpenAPI 3.x or Swagger 2.0 spec. Get instant feedback on errors and structural issues.

Free

API Diff Viewer

Compare two OpenAPI specs side by side. Instantly see added, removed, and modified endpoints with breaking change detection.

Free

API Changelog Generator

Generate human-readable changelogs from any OpenAPI spec. Copy and share with your team.

Free

API Health Check

Test if any API endpoint is healthy. Check uptime, response time, and status codes.

Free

API Version Tracker

Current versions and recent changes of popular APIs. See breaking changes at a glance.

Free

Breaking Change Report

Get a comprehensive report on breaking changes across 20+ popular APIs with migration guides.

Free

API Spec Quality Scorer

Score your OpenAPI spec quality (0-100) with letter grades. Six categories, specific issues, and actionable improvements.

Free