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Professional API Tester Online

Professional API testing tool for developers and QA engineers. Test REST, SOAP, and GraphQL APIs directly in your browser. Send HTTP requests with custom headers, authentication tokens, and request bodies. Features include collection management, keyboard shortcuts (Ctrl+Enter to send), cookie manager, export/import, and response analytics. View formatted responses with syntax highlighting, status codes, and response times. Perfect for API debugging, integration testing, and webhook validation. 100% free, no signup required.

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Initializing JSON Engine...

Preparing local environment

💡 Pro Tips for Power Users

⌨️ Keyboard Shortcuts

  • Ctrl+Enter - Send request
  • Ctrl+S - Save request
  • Ctrl+K - Focus URL bar
  • Esc - Clear response

📦 Collection Management

  • ✓ Save unlimited API requests
  • ✓ Export collections as JSON files
  • ✓ Import collections to share with team
  • ✓ Clone requests for quick variations

🍪 Cookie Manager

  • ✓ Auto-capture cookies from responses
  • ✓ Manually add/edit cookies
  • ✓ Cookies persist across requests
  • ✓ Perfect for session testing

📊 Response Analytics

  • ✓ Response time tracking
  • ✓ Transfer speed calculation
  • ✓ JSON structure analysis
  • ✓ Download responses as files

What is API Testing?

API testing is a crucial part of software development that involves testing Application Programming Interfaces (APIs) to ensure they meet expectations for functionality, reliability, performance, and security. Unlike GUI testing, API testing focuses on the business logic layer of software architecture.

Our online API tester provides a comprehensive solution for testing REST APIs without requiring any software installation. Whether you're a developer, QA engineer, or API enthusiast, this tool helps you validate API endpoints, test different HTTP methods, and analyze responses in real-time.

Key Features of Our API Tester

Complete HTTP Method Support

Test all standard HTTP methods including GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS. Each method is optimized for its specific use case and requirements.

Custom Headers Configuration

Add unlimited custom headers for authentication, content-type specification, API keys, and any other requirements your API endpoints may have.

Request Body Editor

Send JSON, XML, or plain text data with your requests. The editor supports syntax highlighting and validation for better development experience.

Response Analysis

View detailed response information including status codes, response time, headers, and formatted response body with syntax highlighting.

How to Use the API Tester

1

Select HTTP Method

Choose the appropriate HTTP method for your API request from the dropdown menu.

2

Enter API URL

Input the complete API endpoint URL including protocol (https://) and any required parameters.

3

Configure Headers

Add necessary headers like Content-Type, Authorization, API keys, or custom headers.

4

Add Request Body

For POST, PUT, or PATCH requests, add your JSON, XML, or text data in the Body tab.

5

Send and Analyze

Click Send Request and analyze the response including status codes, timing, and data.

Common API Testing Use Cases

REST API Development

Test your REST API endpoints during development to ensure they return correct responses, handle errors properly, and meet performance requirements.

  • • Validate endpoint functionality
  • • Test error handling
  • • Verify response formats
  • • Check status codes

Third-Party API Integration

Test external APIs before integrating them into your application to understand their behavior, response structure, and authentication requirements.

  • • Explore API capabilities
  • • Test authentication methods
  • • Understand response formats
  • • Verify rate limits

Quality Assurance Testing

Perform comprehensive API testing as part of your QA process to ensure reliability, security, and performance before production deployment.

  • • Functional testing
  • • Security testing
  • • Performance testing
  • • Regression testing

API Documentation Verification

Verify that API documentation is accurate by testing actual endpoints and comparing results with documented behavior and response examples.

  • • Validate documentation accuracy
  • • Test example requests
  • • Verify response schemas
  • • Check parameter requirements

API Testing Best Practices

✅ Do's

  • • Test all HTTP methods supported by your API
  • • Validate response status codes and error messages
  • • Test with different data types and edge cases
  • • Verify response time and performance
  • • Test authentication and authorization
  • • Document test cases and expected results
  • • Test API versioning and backward compatibility

❌ Don'ts

  • • Don't test only happy path scenarios
  • • Don't ignore error handling and edge cases
  • • Don't test with production data in development
  • • Don't skip security testing for sensitive endpoints
  • • Don't forget to test rate limiting and throttling
  • • Don't assume API behavior without testing
  • • Don't neglect testing with invalid or malformed data
Frequently Asked Questions
What is an API tester and how does it work?

An API tester is a tool that allows developers to send HTTP requests to API endpoints and analyze the responses. It works by configuring request parameters (method, URL, headers, body) and sending them to the target API, then displaying the response data, status codes, and performance metrics.

Which HTTP methods are supported by this API tester?

Our API tester supports all standard HTTP methods including GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS. You can easily switch between methods using the dropdown selector.

Can I add custom headers to my API requests?

Yes, you can add unlimited custom headers to your API requests. This includes authentication headers (like Authorization, API-Key), content-type headers, and any other custom headers required by your API.

Is this API tester free to use?

Yes, our API tester is completely free to use. There are no registration requirements, usage limits, or hidden fees. All processing is done in your browser for privacy and security.

How do I test POST requests with JSON data?

To test POST requests with JSON data: 1) Select POST method, 2) Enter your API URL, 3) Add Content-Type: application/json header, 4) Enter your JSON data in the Body tab, 5) Click Send Request. The tool will display the response with proper formatting.

Can I save or export API responses?

Yes, you can copy responses to clipboard or download them as JSON files. Use the Copy button to copy formatted response data or Download button to save the response as a file.

What information is shown in the API response?

The API response shows: HTTP status code and message, response time in milliseconds, response headers, formatted response body (JSON, XML, or text), and color-coded status indicators for quick analysis.

Is my API data secure when using this tester?

Yes, all API requests are made directly from your browser to the target API. No data passes through our servers, ensuring your API keys, request data, and responses remain private and secure.

Can I save and export my API requests?

Absolutely! You can save unlimited API requests to your browser's local storage. Use the Export button to download all your saved requests as a JSON file, which you can share with team members or import on another device. Collections include requests, variables, and cookies for complete portability.

What keyboard shortcuts are available?

We support several productivity-boosting keyboard shortcuts: Ctrl+Enter (or Cmd+Enter on Mac) to send requests instantly, Ctrl+S to save the current request, Ctrl+K to focus the URL input, Ctrl+/ to toggle the variables panel, and Esc to clear the response. Click the keyboard icon in the toolbar to see all available shortcuts.

How does the cookie manager work?

Our cookie manager automatically captures cookies from API responses and includes them in subsequent requests, making it perfect for testing session-based APIs. You can also manually add, edit, or remove cookies in the Cookies tab. All cookies are stored locally in your browser and persist across sessions until you clear them.

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