❓ Frequently Asked Questions

API Testing FAQ

Everything you need to know about how to test API endpoints properly, perform REST API testing, and use Test API Chrome extension effectively.

Browse by Category

Find answers to your specific API testing questions

🚀

Getting Started

Basic API testing concepts and how to get started with Test API

🔧

HTTP Requests

Learn how to test different HTTP methods and request types

🔐

Authentication

Testing authenticated APIs and managing API keys securely

⚡

Advanced Features

Environment variables, scripting, and automation tips

How to Test API Calls Properly

Complete guide to effective API testing and endpoint testing

🚀 Getting Started

How do I test API endpoint with Test API Chrome extension?

Testing an API endpoint with Test API is straightforward:

  • Install the Test API Chrome extension from the Chrome Web Store
  • Open the extension popup by clicking the Test API icon
  • Enter your API endpoint URL in the URL field
  • Select the appropriate HTTP method (GET, POST, PUT, DELETE, etc.)
  • Add headers, parameters, or body data as needed
  • Click "Send" to test the API endpoint and view the response

The extension supports both HTTP/1.1 and HTTP/2 protocols for comprehensive endpoint testing.

What's the best way to test REST API online?

Test API provides an excellent way to test REST API online directly from your browser:

  • No account required: Start testing immediately without registration
  • Environment variables: Use {{baseUrl}} and {{apiKey}} for different environments
  • Request history: Keep track of your recent API tests
  • cURL export: Convert your tests to command-line format
  • JSON support: Built-in JSON editor with syntax highlighting

This makes it perfect for RESTful API testing in development, staging, and production environments.

How does Test API compare to other API testing tools?

Test API offers unique advantages for API test online scenarios:

  • Browser-based: No desktop app installation required
  • Lightweight: Fast startup and minimal resource usage
  • Privacy-focused: All data stored locally in your browser
  • Free: No subscription fees or account requirements
  • Chrome integration: Seamless workflow with developer tools

Perfect for developers who need quick REST API test capabilities without heavy client applications. See detailed comparison with Postman.

🔧 HTTP Requests

How do I test POST request with JSON body?

To test POST request with JSON data using Test API:

1. Set HTTP method to "POST" 2. Enter your API endpoint URL 3. Go to "Headers" tab and add: Content-Type: application/json 4. Switch to "Body" tab 5. Select "JSON" format 6. Enter your JSON payload: { "name": "John Doe", "email": "john@example.com" } 7. Click "Send" to execute the request

The extension will automatically validate your JSON syntax and highlight any errors before sending the HTTP POST request.

Can I test GraphQL APIs with Test API?

Yes! While Test API is optimized for REST API testing, it also supports GraphQL:

  • Set method to POST
  • Use your GraphQL endpoint URL
  • Add Content-Type: application/json header
  • Send GraphQL query in JSON body format:
{ "query": "query GetUser($id: ID!) { user(id: $id) { name email } }", "variables": { "id": "123" } }

This allows you to perform comprehensive endpoint testing for both REST and GraphQL APIs.

What are the best practices for API endpoint testing?

Follow these guidelines for effective endpoint testing:

  • Test all HTTP methods: GET, POST, PUT, DELETE, PATCH
  • Validate response codes: Check for 200, 201, 400, 401, 404, 500
  • Verify response format: Ensure JSON structure matches expectations
  • Test edge cases: Invalid inputs, missing parameters, large payloads
  • Check headers: Content-Type, Cache-Control, authentication
  • Monitor performance: Track response times and identify bottlenecks

These practices ensure comprehensive API testing coverage for robust applications.

How do I troubleshoot failed API requests?

When your API test fails, follow this debugging process:

  • Check response status: Understand HTTP error codes (400, 401, 403, 404, 500)
  • Verify URL: Ensure endpoint URL is correct and accessible
  • Validate headers: Check Content-Type, Authorization, Accept headers
  • Inspect request body: Verify JSON syntax and required fields
  • Review response body: Look for detailed error messages
  • Test in isolation: Try simpler requests first

Test API displays full request/response details to help identify issues quickly. Learn advanced debugging techniques.

🔐 Authentication

How can I test HTTP request with authentication?

Test API supports multiple authentication methods to test HTTP request with security:

  • Bearer Token: Add Authorization: Bearer {{token}} header
  • API Key: Include X-API-Key: {{apiKey}} or similar custom headers
  • Basic Auth: Use Authorization: Basic base64(username:password)
  • Custom Headers: Add any proprietary authentication headers

Store sensitive tokens as environment variables to keep them secure and reusable across different API tests.

Does Test API work with CORS-protected APIs?

Test API handles CORS (Cross-Origin Resource Sharing) elegantly:

  • Chrome extension context: Bypasses many CORS restrictions
  • Local development: Perfect for testing localhost APIs
  • CORS headers: Supports preflight OPTIONS requests
  • Proxy support: Can work with development proxies

This makes it ideal for API testing during frontend development where CORS issues are common.

⚡ Advanced Features

What types of API testing can I perform?

Test API supports comprehensive API testing scenarios:

  • Functional Testing: Verify API responses and data accuracy
  • Integration Testing: Test API interactions between services
  • Performance Testing: Monitor response times and API latency
  • Security Testing: Validate authentication and authorization
  • Error Handling: Test edge cases and error responses
  • Data Validation: Ensure correct JSON schema and data types

This covers all essential aspects of RESTful API testing for modern web applications.

How do I use environment variables for API testing?

Environment variables make API testing more efficient and organized:

Create environments like: Development: baseUrl: https://dev-api.example.com apiKey: dev_abc123 token: dev_token_xyz Production: baseUrl: https://api.example.com apiKey: prod_def456 token: prod_token_abc Then use in requests: URL: {{baseUrl}}/users Headers: Authorization: Bearer {{token}}

Switch between environments instantly to test API endpoint across different deployment stages.

How can I automate API testing workflows?

While Test API focuses on manual testing, you can create efficient workflows:

  • Save common requests: Store frequently used API calls
  • Use environment switching: Quickly test across dev/staging/prod
  • Export to cURL: Convert tests to scripts for automation
  • Request collections: Group related API tests together
  • Variable reuse: Extract dynamic values for consistent testing

For full automation, export your Test API configurations to CI/CD pipelines or testing frameworks.

Can I share my API tests with team members?

Test API provides several sharing options for collaborative API testing:

  • cURL export: Share as command-line snippets
  • JSON export: Export request configurations
  • Environment export: Share variable configurations
  • Postman import: Convert to Postman collections
  • Documentation: Include in API documentation

These features enable effective team collaboration while maintaining the lightweight nature of the tool.