An API or Application Programming Interface is a collection of software functions and procedures through which other software applications can be accessed or executed. In API Testing you use software to send calls to the API, get output and log the system’s response. For Agile development, Api Testing becomes important as shorter development cycles put more pressure on automated testing.
What is API Testing: API is an acronym for Application Programming Interface.
In software application (app) development, API is the middle layer between the presentation (UI) and the database layer. APIs enable communication and data exchange from one software system to another.
API testing is a software testing practice that tests the APIs directly — from their functionality, reliability, performance, to security. Part of integration testing, API testing effectively validates the logic of the build architecture within a short amount of time.
API testing can be done on the below aspects:
- Functional Testing
- Load Testing
- Security Testing
Here is a list of top Web Services Testing API Tools. The list contains both open-source(free) and premium web API testing tools.
Postman came to the market initially as a Google Chrome plugin. Its main objective was to test API services. Currently, Postman has expanded its services for both Windows and Mac. So, whether you’re looking for exploratory or manual testing, it’s a great choice.
- Postman allows the writing of Boolean tests and does not require the use of a command line.
- You can extract API data using Postman’s interface.
- This platform consists of built-in tools that give you the ability to interact with an API, collections that let you automate tests, debug, monitor API, run requests, and workspaces that enable you to collaborate.
- Swagger and RAML (RESTful API Modeling Language) formats are supported for designing APIs.
- An easy-to-use REST client.
Katalon Platform brings a hassle-free API testing platform for testers with or without prior programming experience.
- Supports all types of REST, SOAP requests, SSL client certificate.
- Easily import tests from Swagger (2.0 & 3.0), Postman, WSDL, and WADL.
- Built off of data-driven testing methods better test coverage and reliability.
- Create fluent assertions in BDD style with AssertJ support.
- Support set up API test data using UI testing.
- Provide insightful test report dashboards of all testing stages for better monitor and collaboration across teams.
The most widely popular tool for API testing in the world, SoapUI allows you to test REST and SOAP APIs with ease – as it has been built specifically for API testing.
- With its point-and-click and drag-and-drop functionality, it simplifies complex tasks (such as working with JSON and XML) and rapidly creates tests.
- Simulate how consumers interact with your APIs by loading data from Excel, files, and databases.
- The user can access the complete source code of SoapUI via the free package
- Effective data-driven testing since it loads data from databases, excel, and files to simulate users’ interaction with the APIs.
- SoapUI supports Data-driven testing
- It supports REST (Representational State Transfer), SOAP (Simple Object Access Protocol), JMS (Java Messaging Protocol), JDBC (Java Database Connectivity), and many other protocols.
Created to perform load testing, JMeter is now popular for functional API testing. Moreover, JMeter 5.4 came out in December 2020 with additional bug fixes and core enhancements. The user experience is also better than the previous versions. Let’s check out the primary features of JMeter.
- By integrating JMeter with Jenkins, users can include API tests within CI pipelines.
- The tool is very flexible and allows testers to customize it according to their requirements.
- It can be used with both dynamic and static resources to test performance.
- Great for working with CSV files, and it allows teams to create unique parameter values for testing.
- It performs load and performance tests for a wide variety of server types.
Apigee is a cross-cloud API testing tool. It allows the user to measure and test API performance, supports and build API using other editors like Swagger. It offers security and governance policies across all APIs.
- Allows to design monitor, deploy, and scale APIs
- Easily create API proxies from the Open API Specification and deploy them in the cloud
- Identify performance issues by tracking API traffic, error rates, and response times