What is API Testing? A Guide to Testing APIs

API test automation requires less code than automated GUI tests, resulting in faster testing and a lower overall cost. Load testing is used to see how many calls an API can handle. This test is often performed after a specific api testing best practices unit or codebase is completed to determine whether the theoretical solution can also work as a practical solution when acting under a given load. The request and response headers along with the response body will be displayed.

REST API Testing

API Analytics Understand how your customers are using your API. Log all your APIs to get deep API metrics and payloads they are sending. Synthetic Monitoring Ensure availability and uptime in HTTP, SSL, TCP, UDP, DNS and be the first to know if your app is slow or broken. Infrastructure Monitoring Get a comprehensive view of the health, CPU, Memory, Disk utilization, packages of your servers and hosts in real-time.

Best Practices for REST API Testing

A REST API is an API that conforms to the concept of modeling and accessing an application’s data simply and flexibly. Using this style to create basic tests of a few core pieces of functionality is a powerful way to validate your live service. Doing so may require some careful attention to setup and teardown to ensure that the tests run in a way that they do not directly affect customer data. Facilitates the building, execution, and automation of performance and functional testing. Subsequently, it’s the most powerful monitoring tool for SOAP and REST. Version 0.9.6 of Karate DSL includes async capability-based support for WebSocket.

Now you’re ready to select an API testing tool that can help automate or simplify the API testing process. When evaluating different API testing tools, it’s important to know what kind of API you’ll be testing, what kind of tests you’ll be running, and what your budget is. This broader test coverage makes it easier to identify any bugs in the unit, database, and server levels. Many companies use microservices for their software applications as they allow software to be deployed more efficiently.

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The most common API output you need to verify in API testing is the response status code. Generally, APIs of an application are used to manipulate its resources in reading , creating , updating and deleting . Knowing the purpose of the API will set a firm foundation for you to well prepare your API testing data for input and output.

This trend points to the growing importance of APIs—and, by extension, API testing—to every company’s digital strategy. It’s important for teams to employ a logical and scalable organizational framework for their API test suite—especially as the API grows and changes. https://www.globalcloudteam.com/ For instance, teams should tag each test according to its purpose, which makes it easier to execute batches of related tests with a single command. They should also create distinct test suites for each API resource—and keep unit tests separate from end-to-end tests.


And if you are curious about knowing more, do not hesitate to get in touch with our team. Well, put simply, and API is a set of rules which help programs to communicate with each other. The developers create APIs on the servers, which permit clients to talk to them. Whether a typical consumer knows it or not, APIs are utilized in the services and applications they user every day. REST is a software design pattern typically used for web applications.

REST API Testing

It will not make sense if the selected tool supports testing RESTful services while your AUT is using SOAP services. In a testing project, there are always some APIs that are simple with only one or two inputs such as login API, get token API, health check API, etc. However, these APIs are necessary and are considered as the “gate” to enter further APIs. Focusing on these APIs before the others will ensure that the API servers, environment, and authentication work properly.

Validating REST API Parameters

For appending, the query parameter goes to the end of the URL by adding ‘? But the best thing about Postman is that if you have the API URL, you can simply paste it to get the status code, and the same rule applies to all other methods. It’s very simple, but it’s enough for our work and for practicing. If you need to load test you need to add your own server’s name. Verify that the response status code is returned as specified in the requirement, whether it returns a 2xx or error code. Does the tool support test the API/Web service types that your AUT is using?

  • Obviously, the killer feature here is a framework that learns with each test suite execution and maintenance activity.
  • REST APIs are crafted with several parameters, including query parameters, request methods, and request URIs.
  • Private API – Private APIs are not made publically available for anyone to use.
  • Launch the app Advanced REST client , once it is installed successfully.
  • Facilitates the building, execution, and automation of performance and functional testing.

It is painful if errors occur because you will have to debug the data flow generated by API in a sequence. There are some cases in which you need to call a series of API to achieve an end-to-end testing flow. However, these tasks should come after all APIs have been individually tested.

Best Tools for REST API Designers, Developers, and Testers

Due to this fact, it is vital that APIs be thoroughly tested, as they play a significant role in development with other applications and integrations and a user’s experience. The most touch parts of API testing are not either sending requests or receiving the response. It is common that testing a few first APIs such as login, query some resources, etc. is quite simple.

Nevertheless, one of the most vital constraints is that the web application should be able to deliver the data whenever a command is given. Our RESTful API in this blog post is so simple that we do not need to send headers, and you can skip this step. JSON, or JavaScript Object Notation, is a way to store information in an organized, easy-to-access manner.

REST API Testing and Manual Test Cases

Before a request you may provide additional http headers which will be used in a next request to set authorization or expected content format. JSON Schema validation- In simple words, JSON Schema describes the data format/types i.e. boolean, int, string etc used by the developer while creating the APIs. Moreover, it is not only used to validate data through automation testing but also provides clear human & machine-readable data. By using Query Param, one can get the specific content from the server.