Which tool to use for API testing?

Which tool to use for API testing?
Scope of this article will introduce you to a list of the best rated API testing tools available today.

A testing before providing to users is an extremely important work in the API development process.

It helps to determine if the APIs are built to meet expectations in terms of functionality, performance, reliability, security, completeness, etc.

In addition, it also ensures as well as minimizes errors when integrating APIs into applications.

In today's market, there're a variety of tools to support API testing, but which one is worth your trust and choice?

Stay tuned for the following post!


It can be commented, Postman is an extremely familiar and highly appreciated name in API testing tools thanks to the following outstanding advantages:

  • Useful.
  • An intelligent automation API testing tool.
  • Manual API testing is also supported.
  • Friendly and eye-catcing interface.
  • Simple for use.
  • Does not require users to learn new programming languages.
  • Includes REST API functionality without writing any code.
  • REST client can be used quickly and easily.
  • Allows sending HTTP request with all methods (GET, POST, PUT, DELETE, etc.).
  • A request header is editable.
  • Post data in multiple formats (text, JSON, key-value, etc.).
  • Results are returned in many formats (text, images, XML, JSON, etc.).
  • Built-in special features such as run, test, document, monitor and support:
    • Swagger and RAML format.
    • GRAPHQL variable.
    • Diagram.
    • GRAPHQL query autocomplete function set.
  • Manage public data in the workspace and share knowledge links with your team easily.
  • All history of requests will be saved, making it convenient for reuse.

It's often used by developers during the product development phase, specifically in unit testing.

With Postman, users can completely check the API quality through the returned results without worrying about the software interface.

Currently, Postman has expanded and become a solution with many versions suitable for all different operating systems such as MacOS, windows (32 bit - 64 bit), Linux, Chrome.

Dùng công cụ nào để kiểm tra API?


SoapUI is a familiar open source tool in the field of APIs, from SmartBear.

It supports all the standard protocols and technologies for API/REST API/SOAP/web services functional automation testing, currently available in free and pro versions.

Of course, with the pro version, users will experience more advanced and interesting features.

Moreover, in the premium version, SoapUI has an intuitive, simple and friendly interface.

Free versionPro version
  • Allow access to the entire source code and create priority features.
  • Support to create tests quickly and easily, with just drag & drop - point - click.
  • Load tests can be reused.
  • Powerful and big data driven testing.
  • Allowed to simulate how end users interact with APIs through data uploaded from file, base and Excel.
  • Native CI/CD integration.
  • Supports asynchronous testing.

Users can also apply SoapUI in regression and load testing.

Besides, SoapUI also allows users to perform non-functional tests such as performance and security.

Dùng công cụ nào để kiểm tra API?


JMeter is an open source tool written in Java, often used for performance testing and load measurement of products in the middle or near release phase.

Besides, it also supports API functional testing.

Possessing outstanding advantages, JMeter is preferred by many users in the community:

  • Supports caching and re-running test results when offline.
  • Have ability to automatically work with CSV files.
  • Allows users to create unique parameters and variables for API testing at lightning speed.
  • Support testing performance and load on both static - dynamic sources in many types of servers.
  • Runs on many different operating systems.
  • Completely free for use.

Dùng công cụ nào để kiểm tra API?

Katalon Studio

Katalon Studio is a comprehensive, automated and completely free API testing tool.

It provides a common environment for creating and executing UI functions, API/web services, mobile.

Below are some outstanding features from Katalon Studio:

  • Simple and fast installation.
  • User-friendly interface.
  • Easy to use, even for beginners or inexperienced programming.
  • Build flexible test suites.
  • A feature set focuses primarily on performance for projects of all sizes.
  • Hundreds of keywords for creating test cases.
  • Supports requests for both SOAP API/REST API, SSL client certificates and manual testing methods.
  • Data Driven approach, for better reliability and test coverage.
  • Enables native CI/CD integration.
  • Runs on many platforms such as windows, MacOS…
  • Recognized as the customer's choice (gartner peer insights) for software test automation in 3 consecutive years.

Dùng công cụ nào để kiểm tra API?


Besides SoapUI, ReadyAPI is also a popular API testing tool from SmartBear.

ReadyAPI is loved by users for the following outstanding features:

  • As 4-in-1 tool that performs tests simultaneously:
    • API performance.
    • API function.
    • API security.
    • APIs and virtual web.
  • Support functional - load - security testing of RESTful, SOAP, GRAPHQL and web services.
  • Ensure complete quality testing for all web services.
  • Command line support and API integration testing with CI/CD pipeline.
  • Enables comprehensive and data-driven creation of API functional tests.
  • Remove dependencies.

Dùng công cụ nào để kiểm tra API?


As a cloud testing tool written from JavaScript, Apigee allows users to measure and identify performance related factors through API traffic - error rate - response time.

Besides, it also supports design monitoring, building and extending the API through other editors like Swagger.

With this tool, users can also easily create API proxies based on open specifications and deploy them in the cloud.

Apigee has been named one of the top tools at the “gartner magic quadrant 2019” for full lifecycle API management 4 years in a row.

Dùng công cụ nào để kiểm tra API?