For manual software testing engineers, having access to reliable and free tools to send API requests is essential for testing RESTful web services. Below are some of the best free tools that are beginner-friendly and widely used in the industry:
Postman
Overview: One of the most popular tools for sending API requests and testing RESTful web services.
Key Features:
Send GET, POST, PUT, DELETE, and other HTTP requests.
View formatted JSON responses.
Create and save collections of requests for reusability.
Add headers, query parameters, and body payloads easily.
Why Use It?: Postman is highly intuitive and perfect for both beginners and advanced testers. It also supports collaboration for team environments.
Platform: Windows, macOS, Linux, and Web version.
Website: Postman
How to send requests guide: Postman Learning page
Insomnia
Overview: A lightweight alternative to Postman for sending and testing API requests.
Key Features:
Simple and clean user interface.
Supports REST, GraphQL, and gRPC requests.
Allows adding authentication headers, body payloads, and parameters.
Built-in JSON viewer for easy response inspection.
Why Use It?: Great for testers who prefer a minimalist tool with essential features.
Platform: Windows, macOS, and Linux.
Website: Insomnia
How to send requests guide: Insomnia Learning page
Hoppscotch (Formerly Postwoman)
Overview: A free, open-source, web-based API testing tool.
Key Features:
Send HTTP requests directly from your browser.
Supports REST, GraphQL, and WebSocket requests.
Lightweight and doesn’t require installation.
Why Use It?: Perfect for quick API testing without installing additional software.
Platform: Web-based (works in any modern browser).
Website: Hoppscotch
How to send requests guide: Hoppscotch Learning page
cURL
Overview: A command-line tool for sending HTTP requests.
Key Features:
Send requests directly from the terminal or command prompt.
Supports all HTTP methods and advanced features like authentication, cookies, and proxies.
Lightweight and does not require a graphical interface.
Why Use It?: Ideal for testers comfortable with the command line or when automating API tests in scripts.
Platform: Cross-platform (pre-installed on most Unix-based systems like macOS and Linux).
Website: cURL
For manual software testing engineers, tools like Postman, Insomnia, and Hoppscotch are excellent starting points due to their user-friendly interfaces and rich feature sets. Meanwhile, command-line enthusiasts can rely on cURL for flexibility.