While writing actual code is often the most comprehensive and flexible way to test APIs, there are indeed several tools and techniques for API testing without needing to write code. These tools typically provide a user-friendly interface to define, execute, and validate API requests and responses. Here's a breakdown of common approaches and popular tools:

1. GUI-Based API Testing Tools (Most Common)

These tools offer a visual interface for defining API requests (method, URL, headers, body, authentication) and then asserting the expected response (status code, headers, body content). They are the easiest way to get started with API testing.

• Postman: The industry standard. It's free for individual use and smaller teams. Postman is great for:


• Creating API requests with a user-friendly interface.


• Setting headers, request bodies, and authentication details.


• Sending requests and viewing responses (status code, headers, body).


• Writing assertions to validate the response (e.g., check status code, specific data in the response).


• Creating collections of API requests to represent common workflows.


• Environments for managing different API configurations (e.g., dev, staging, production).


• Mocking APIs to simulate API behavior for testing purposes.


• Collaboration features for teams.


• Supports many protocols including REST, SOAP, GraphQL.


• Insomnia: Another popular option similar to Postman. It's known for its sleek interface and GraphQL support. Like Postman, it has a free version.


• Easy to use for REST and GraphQL APIs.


• Has features for organizing API requests.


• Supports environment variables.


• Paw (macOS only): A powerful API testing tool specifically designed for macOS. It focuses on performance and usability. While Postman and Insomnia are cross-platform, Paw provides a native macOS experience.

• Request Building: Intuitive interfaces for defining API requests.


• Parameterization: Ability to use variables and data sets to create dynamic requests.


• Assertions: Easily define validation rules to check the response data.


• Organization: Group requests into collections or folders for better management.


• Environments: Manage different configuration settings for various environments (dev, staging, production).


• Reporting: Generate reports on test results.


• Authentication: Support for various authentication mechanisms (e.g., API keys, OAuth, Basic Auth).

These platforms offer a more structured approach to API testing, often incorporating workflow automation and advanced features like data-driven testing and integration with CI/CD pipelines.

• Apigee (Google Cloud): A comprehensive API management platform that includes testing capabilities.


• ReadyAPI (SmartBear): A powerful platform for API testing, including functional, performance, and security testing. (Commercial, but offers trials)


• Parasoft SOAtest: Specialized for testing service-oriented architectures (SOA) and APIs. (Commercial)

• Visual Workflow Design: Create test workflows using a graphical interface.


• Data-Driven Testing: Test APIs with different datasets to ensure robustness.


• CI/CD Integration: Integrate API tests into continuous integration and continuous delivery pipelines.


• Advanced Reporting: Generate detailed reports on test execution and results.


• Security Testing: Includes capabilities to test for vulnerabilities in APIs.

These are cloud-based platforms designed specifically for API testing. They often provide features for monitoring, performance testing, and functional testing.

• Runscope (now part of LoadView/Dotcom-Monitor): Offers API monitoring and testing.


• Assertible: A cloud-based API testing platform that integrates with CI/CD pipelines.

While these tools can be used without coding, they often benefit from scripting for more complex scenarios. However, they're still worth knowing about.

• curl: A command-line tool for making HTTP requests. While you don't write code, you do write command-line arguments to construct the request. Very useful for quick and dirty API checks. Example:

curl -X GET "https://api.example.com/users/123" -H "Authorization: Bearer your_api_key"

• httpie: A modern command-line HTTP client with a more user-friendly syntax than curl. Similar caveat as curl - you construct commands.

http GET https://api.example.com/users/123 Authorization:"Bearer your_api_key"

When is No-Code/Low-Code API Testing Enough?

• Simple API Calls and Assertions: If you only need to test basic API functionality (e.g., check status codes, verify simple data in the response), GUI-based tools are sufficient.


• Exploratory Testing: When you need to quickly explore an API and understand its behavior, these tools are invaluable.


• Regression Testing (Basic): For re-running a set of predefined tests to ensure that changes haven't broken existing functionality.

• Complex Assertions: When you need to perform intricate data validation or custom logic.


• Data-Driven Testing with Complex Data: When you need to test with large and complex datasets that are difficult to manage manually.


• Performance Testing at Scale: No-code tools may not provide the scalability and control needed for rigorous performance testing.


• Advanced Security Testing: Specific security testing requirements often necessitate custom code to craft malicious requests and analyze responses.


• Highly Dynamic APIs: When dealing with APIs that change frequently, coding can provide more flexibility to adapt to changes.

• Your budget: Many tools have free tiers or open-source options.


• Your technical skills: If you have limited coding experience, GUI-based tools are a good starting point.


• Your API's complexity: More complex APIs may require low-code platforms or even coding.


• Your team's needs: Consider collaboration features, reporting, and integration with your existing tools.


• The specific type of testing you need: Functional, performance, security, etc.

• Download and install Postman or Insomnia. They're free to get started.


• Read the documentation or watch tutorials. Learn how to create requests, set headers, and validate responses.


• Start with simple API endpoints. Gradually increase the complexity as you become more comfortable.


• Practice writing assertions. This is the core of API testing.


• Organize your tests into collections. This will make them easier to manage and run.