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Developer Guide

API Testing & Debugging Best Practices

Master API testing, debugging, and monitoring. Learn professional tools, techniques, and strategies for building reliable APIs and integrations.

Why API Testing Matters

API testing is crucial for ensuring your applications work reliably. Unlike UI testing, API testing validates the business logic, data responses, and security of your application at the service layer.

Proper API testing catches bugs early, ensures data integrity, validates security, and improves overall application reliability.

Essential API Testing Tools

HexDataTools API Tester

Professional browser-based API testing with collections, environments, and code generation.

Try API Tester Enterprise

Postman

Industry-standard API platform for building, testing, and documenting APIs.

cURL

Command-line tool for making HTTP requests, perfect for automation and CI/CD.

Testing Strategies

Functional Testing

  • Validate request/response formats
  • Test error handling
  • Verify status codes
  • Check data validation

Performance Testing

  • Response time testing
  • Load testing
  • Stress testing
  • Spike testing

Debugging Best Practices

  • Use detailed logging: Log request/response data, headers, and timestamps
  • Test in isolation: Remove dependencies to pinpoint issues
  • Verify authentication: Check tokens, API keys, and permissions
  • Inspect network traffic: Use browser DevTools or proxy tools
  • Check rate limits: Verify you're not hitting API throttling

Common HTTP Status Codes

Success Codes (2xx)

  • 200 OK - Request succeeded
  • 201 Created - Resource created
  • 204 No Content - Success, no body

Client Errors (4xx)

  • 400 Bad Request - Invalid syntax
  • 401 Unauthorized - Auth required
  • 404 Not Found - Resource missing