The 9 API Testing Tools to Watch Out in 2021

Ever since the technology and procedure have progressed a lot, organizations or teams prefer to have quicker testing feedbacks. Since we can notice with the shift-left trend to DevOps, Application Programming Interface testing has become a significant and crucial factor on CI/CD. Automated testing efforts can bring extra worth with the right API testing in place, rather than depending on time-consuming User Interface testing only. The interest in API tests has been growing progressively over the last few decades, as per Google Trends.

Why API testing is required?

• Scrutinizing an application at the API level would be catastrophic thus it is better to do it at first

• Main functionalities of the Application Programming Interface can be validated

• Consumes less time than that of Graphical User Interface functional tests

• Testing data is mostly derived as XML or JSON. Thus the procedure, not language dependant

• Can be easily integrated with Graphical User Interface tests

Top 9 API Test Tools to Look Out in 2021

1. Postman

Postman being originally come to the market as a Chrome plugin, is now expanding its solution with the native version for Windows, Linux, and Mac. It is a great option for API tests for those who do not wish to deal with coding in an IDE (integrated development environment) using a similar language as the software developers. So, whether you are searching for manual or exploratory testing, it is a great choice.

Crucial Features:

• With the help of this tool, you can create automated tests, you can monitor the API, execute debugging, and run requests
• Its interface enables users for extracting web API data
• Supports Continuous Integration/ Continuous Delivery service with Newman
• Postman allows writing Boolean testing & is not based on the command line
• Counts built-in collections, tools, & workspaces
• Supports several formats, counting Swagger and RAML
• Can be used for both exploratory and automated tests

Official Website-Postman

2. Rest Assured

It is one of the most popular API tools that facilitate simple tests of REST services. REST Assured is an open-source or free tool and a Java domain-specific language perfectly designed to make the REST test easier. Besides, the newest version has fixed OSGi support-concerned problems. It also provides additional assistance when it comes to making use of Apache Johnzon. Starting with version 4.2.0, this tool requires Java 8 or higher. It is bundled with countless features, allowing users to continue tests without any coding.

Crucial Features:

• Supports any HTTP technique but has an explicit hold for several kinds of commands like PUT, POST, DELETE, GET, PATCH, OPTIONS, and HEAD & comprises specifying as well as validating e.g. headers, parameters, cookies, and body effortlessly
• Built-in functionalities make sure that users do not require to perform coding from scratch
• Users do not require an extensive understanding of HTTP
• Support BDD Given/ Then / When syntax
• The sole framework can have a blend of REST tests and User Interface
• Flawless integration is possible with the Serenity automated framework
• Provides several authentication mechanisms

Official Website-Rest Assured

3. JMeter

Introduced to perform load testing, this tool is now well-liked for functional API tests. Moreover, JMeter 5.4 brings on in Dec 2020 with extra core enhancements and bug fixes. The user experience is also far better than the last versions. The latest release is JMeter 5.2 in Nov 2019. The JMeter has been packed with varied enhancements and features, several bug fixes, and enhanced user experience, like JMESPath extractor, new protocol, JDBC improvements, HTTP Samplers, and StringtoFile.

Crucial Features:

• JMeter is compatible with dynamic and static resources to test performance.
• The integration between Jenkins and Apache JMeter enables users to include API tests within Continuous Integration pipelines.
• Automatically works with CSV files and enables teams to create unique parameter values for tests.
• It is a very flexible API testing tool and assists in customization as per the tester
• Supports manifold protocols for an effective test process

Official Website-JMeter

4. Tricentis

It is one of the robust web services test tool giving the edge of the CD feature. Tricentis accelerates test with a script-less, no-code approach for E2E (end to end) automated testing. Tricentis’ 400+ users comprise global names from the Top 500 brands like Whole Foods, ExxonMobil, HBO, BMW, Toyota, Allianz, Deutsche Bank, Starbucks, Lexmark, Orange, Vodafone, A&E, Vantiv, UBS, and Telstra.

Crucial Features:

• Supports a wide range of protocols counting AMQP, HTTP(s) JMS, TIBCO EMS, SOAP, IBM MQ, Rabbit MQ, NET TCP REST,
• It integrates into the DevOps and Agile Cycle
• Best API automated tools which use model-based automated testing that makes script maintenance simple
• Enables E2E test as API tests could be used amid packaged apps, mobile, cross-browser, etc.

Ofiicial Website-Tricentis

5. SOAP UI

The popular and most widely used tool for API tests in the world, SoapUI enables you to test SOAP and REST APIs with no difficulty — as it has been built especially for API tests. It is a test automation tool for REST and SOAP APIs. SOAP UI acts as a headless functional test tool dedicated to API test and using this tool allows users to get the full source and build the preferred traits besides these capabilities. SoapUI Pro is used by 1000s of renowned companies across the globe, counting: Microsoft, Apple, Cisco, HP, Oracle, eBay, NASA, FedEx, MasterCard, Pfizer, and Intel.

Crucial Features:

• Fast and Simple Test Creation i.e. drag-and-drop, point-and-click, functionality makes complex tasks (such as working with XML and JSON) easy
• Robust data-driven test that is load data from databases, excel and files to simulate the way users interact with the APIs
• Reuse the functional test cases as security scans and load testing in just a few clicks
• Flawless Integrates with thirteen API management platforms, supports SOAP, REST, IoT, and JMS

Official Website- SoapUI

6. Apigee

Google (Apigee) is a cross-cloud Application Programming Interface management platform and powered by Javascript, enabling users for measuring and testing API performance, builds, and supports API using editors such as Swagger. For 5 consecutive times, it is accepted as a Leader in the Gartner Magic Quadrant for Full Lifecycle Application Programming Interface management. Starting from Feb 2019 with the launch of version 4.19.01, it gave users even extra flexibility for managing their APIs with traits such as TLS security, Open API 3.0 support, virtual host management improvements, self-healing with apigee-monit, and more software support. The current 4.19.6.04 announces in April 2020 with slight bug fixes merely.

Crucial Features:

• Identify performance problems by tracking API traffic, error rates, and response times,
• Simply generate API proxies from the Open Application Programming Interface Specification and employ them in the cloud
• On-premises (in a private cloud) or cloud and often using a hybrid deployment model
• SOC2, HIPAA, PCI, and PII for applications and Application Programming Interfaces
• Apigee is purpose-built for online business, & the data-rich mobile-driven Application Programming Interfaces and applications that power it
• Its full lifecycle Application Programming Interface management platform gives the dashboards, visualization tools, and reports to assist measure the data that flows across Application Programming Interfaces in real-time
• Manages the procedure to design, develop, publish, deploy, version, governance, monitor accessibility, and measure performance

Official Website- Apigee

7. Test Mace

It is one of the modern powerful cross-platform tools that assist to work with an API and generate automated Application Programming Interface tests.

Crucial Features:

• To create and test complicated scenarios rapidly
• To Create tests without actual programming
• CI/CD support
• Powerful auto-complete trait and highlighting of present functions, variables values, etc.
• The well-organized human-readable file format and project structure enable you for storing your project in the version control system review and repo testing and scenarios
• Advanced JavaScript support in the built-in code editor, counting the static analyzer and auto-complete trait
• Flexibility- Calculated expressions in any text field, even in the headers area or address bar
• Cloud synchronization

Official Website- Test Mace

8. Assertible

This is a well-accepted API testing tool that constantly tests web services and concentrates on reliability and automation. In October 2019, this tool introduced the newest trait called Encrypted variables, which offers a fresh way to store passwords, tokens, and confidential data fields requisite by tests to advance API test security practices. Encrypted variables aren’t merely trivial to use, however, build on the cryptographically sound method for safe storage.

Crucial Features:

• Supports automation Application Programming Interface tests through every single step of a CI and CD pipeline
• Supports running Application Programming Interface testing after deployment
• It can be integrated with some of the other tools like Zapier GitHub, and Slack
• Support authenticating Hypertext Transfer Protocol (HTTP) reactions with turn-key assertions like JSON Path data integrity checks and JSON Schema validation
• The synchronize feature allows users to upgrade tests when their specifics change, you don’t have to manually update their tests after adding-up new parameters or modifying the response of the Application Programming Interface.

Official Website: Assertible

9. Swagger

It is an API testing tool that enables users to begin their security, performance, and functional test straight from the Open Application Programming Interface Specifications. Swagger tooling & Ready Application Programming Interface platform make it simple to rapidly generate, manage, and implement Application Programming Interface tests in the pipeline. Open Application Programming Interface Spec version 3.0 in March 2019 came with the newest traits Swagger Hub Domains. With this amazing trait, software developers can take commonly used objects, path items, response, and accumulate them in individual files to be referenced amid manifold distinct Application Programming Interface definitions. Such re-usable Domains can be published, shared, and versioned for collaborative feedback amongst big teams.

Crucial Features:

• Swagger Inspector offers capacities to inspect Application Programming Interface request-responses and ensure they execute as expected
• Import user’s Application Programming Interface definitions to automatically generate assertions against endpoints, validate schema rules & insert synthetic data into parameters with zero trouble
• Generate complicated load scenarios for testing the scale and performance of the Application Programming Interface easily
• Support every kind of services from GraphQL, SOAP to REST,

Official Website: Swagger

What are the advantages of API Testing?

• Advance Testing

With the Application Programming Interface test, once the logic is designed, testing can be built to authenticate the correctness in data and responses. We do not need to wait for several teams to end their work or for complete apps to be built — test cases are isolated plus ready to build straight away.

• Simple Test Maintenance

User Interfaces are continually changing as well as moving around based on how they are accessed — screen orientation, devices, browsers, etc. This forms a nightmare scenario where testing is being continuously rewritten to continue with the real code in production. Application Programming Interface changes are very much controlled and infrequent — sometimes Application Programming Interface definition files such as OpenAPI Spec can aid to make refactoring testing only seconds of work.

• Rapid Time To Resolution

When Application Programming Interface tests fail, we know accurately where our system broke plus where the imperfection can be found. This aids in reducing time triaging bugs between integrations, builds, and even distinct team-members. The isolated, small footprint of an Application Programming Interface testing is perfect for rapid MTTR stats, a worthy KPI for DevOps groups.

• Speed & Coverage of Tests

Three hundred User Interface testing may take 30 hours to execute. Three hundred Application Programming Interface tests could be executed in three minutes. That means you will search for more bugs in lesser time, whilst also being about to fix them straight away.

Final Verdict

Out of the above-mentioned top API test tools, Postman, SoapUI, and Katalon Studio provide free and paid plans. Whilst JMeter, REST-Assured, and others are free or open-source tools that are accessible free of cost.