Top 25 API Testing Tools [Selected for 2024]

Last updated on August 3rd, 2024 at 11:56 am

In simple words, an API also called Application Programming Interface is the messenger that allows two software to transfer data and have a discussion with each other. Now the question arises, how an app remains entirely functional because it is constructed each and every time without conceding to user privacy? The response to this is API testing tools. 

Keeping this scenario in mind, we are presenting the list of 25 best API testing tools for 2024.

Here is the list of the Top API Testing Tools in 2024

1. Katalon Studio 

It has been famous as the Gartner Peer Insights Customers’ selections for software test Automation for 3 consecutive years, Katalon Studio is the leading testing tool of automation answers for API, Web, and Mobile and Windows applications.

 The main features include::

 • Easy-to-use UI and productivity-centric options for comes of all sizes

 • Supports REST, SOAP requests, and SSL consumer certificates

 • Enable test import from Swagger (2.0 & 3.0), Postman, WSDL, and WADL

 • Native CI/CD integrations (Jenkins, Azure DevOps, CircleCI, Dockers, etc.)

 • Data-driven test techniques that lead to higher test coverage and reliableness

 • AssertJ support to make fluent assertions in BDD vogue

 • Support API take a look at knowledge setup victimization UI testing

 • Built-in news platform to change reports and activities across tool stacks: version management systems, CI/CD, test automation tools, and ALMs

 • Free API testing courses and power tutorials on Katalon Academy

2. AirBorne

It is a well-known API automation testing framework with a Ruby-based RSpec-driven framework. Since mobile may be a programming framework, it’s no program excluding the computer file to make code. Besides that, to use mobile testers got to keep in mind a number of essential strategies within the toolset and a few Ruby and RSpec fundamentals.

 In 2020, mobile was updated to version v0.3.5 with minor bug fixes. It is a free-to-use and open-source API testing tool that testing groups might use to satisfy their needs.

3. Citrus Framework

The tests give a Java fluent API to specify the test logic and are absolutely automatic. Citrus will act on either side as a consumer or a client throughout the check once the replacement of the particular request/response message is over the wire.

 Citrus 3.1.0 is the latest stable version. It’s on the market within the central virtuoso repository so you’ll be able to add Citrus as a virtuoso dependency to your project. It’s a free, open-source tool with custom scripting functionalities that you just will utilize your programming skills to suit project needs.

4. Taurus

Taurus could be a free and open-source framework for easy and direct API testing as a result of its ease to find out. Taurus helps you hide the quality of running performance tests while not learning any programming languages; instead, all you wish to know is the basic YAML structure of Taurus.

 Taurus v1.15.4 updates varied options, improves user expertise, and fixes bugs.

5. Hoppscotch

Hoppscotch could be a tool within the API tool class of the technology stack. it’s a free and quick API request generator with a minimalistic UI style, permitting you to send requests and get/copy responses in a period of time. Therefore, you’ll be able to produce requests quicker, saving valuable development time. In August 2021, Hoppscotch was updated to version v2.2.0 with some minor bugs being mounted. As an open-source tool, you’ll be able to be happy to customize it to your project needs.

6. Pyrettest

It is a Python-based REST API testing platform that supports tests in JSON or YAML config files, no coding information is needed.

 The key features include::

 • Generate and validate mechanisms to make complete take a look at situations

 • Allow straightforward preparation on-server for smoke tests/health checks with tokenish dependencies (pycurl, pyyaml, optionally future)

 • Returns exit codes on failure to fit into machine-driven configuration orchestration tools

 In 2016, the newest version, v1.7.1 was discharged with a hard and fast JSONschema extension in Python three and accessorial take a look at coverage. This tool is best used for reposeful Apis.

7. API Fortress

Testers and developers will produce and automatize useful tests since API fortress could be a continuous platform for API testing.

 The key features include::

 • Easy-to-use intuitive UI for any talent level

 • Plug-and-play stimulates your continuous API Testing

 • Support net Services, Test REST, SOAP, GraphQL, and Microservices

 • It’s a web-based cooperative tool for groups that helps testers work inside a browser and needs no downloads.

 The latest version in September 2020 offers several new options which permit a check to continue when a fatal error, improve multipart for on-prem and cargo testing and K/V store for mocking services. API fort is liberated to use and straightforward to customize to the particular needs of your project.

8. Rest Console

This tool could be a REST/HTTP shopper for Google Chrome that permits users to ascertain and construct custom protocol requests to check with any relaxing API service.

 The key features include::

 • Construct POST or place body via raw input

 • Support to change custom headers through intuitive UI

 • Assist users in making question parameters relaxed

 • Able to be used for many authentications like Plain, Basic, OAuth

 • Supports customizable interface

 The most recent unleash, Rest Console v4.0.2 has been upgraded with many options to reinforce user expertise and bug fixes (e.g., oAuth enhancements, collapsible sections, Clickable Links in Response, UI enhancements).

9. Karate DSL

This new API testing tool assists users in making situations for API-based BDD tests merely while not writing definition steps. Indeed, KarateDSL creates those definitions itself, therefore users will quickly kickstart the API testing.

 The key features include::

 • Build on prime of Cucumber-JVM

 • Run a take a look at and generate reports likewise to any customary Java project

 • Supports configuration switching/staging, multithreaded parallel execution

 The latest revision, martial art UI one.2.0, was discharged with a slew of recent options, together with redesigned hypertext mark-up language reports, call-Single-Cache, martial art golem Windows for Windows Desktop app automation, and increased tree walking in UI Tests. Also, martial art UI permits you to put in writing tests in any language which will handle HTTP, JSON, or XML.

10. SOAP UI

This headless useful testing tool is devoted to API testing. It permits users to check REST and SOAP Apis and net Services with no hassles.

 For the Free package, users can:

 • Acquire the complete source code and build the most popular options at hand

 • Develop test effortlessly with Drag and drop, Point-and-click

 • Reuse load source codes and security scans for useful test cases in exactly many steps with the Reusability of Scripts feature

 For the professional package, users can:

 • Powerful knowledge-driven testing – which suggests users will simulate however customers move with the Apis due to data loaded from files, databases, and Excel

 • Upkeep native continuous development and continuous integrations and asynchronous testing

 The latest version SoapUI five.6 has updated third-party libraries (org.apache.HTTP parts, commons-logging, commons-codec, and JUnit) and removed unused third-party libraries like Jackson, KeenIO.

 Update: SoapUI currently disables the Load and Save project scripts by default to boost testing security.

11. Assertible

Assertible is an API testing tool that focuses on automation and responsibility.

 The key features include::

 • Backing automation API tests during CI/CD pipeline

 • Assist in running API tests when deployments and integrating with acquainted tools (e.g., GitHub, Slack, and Zapier)

 • Support verificatory HTTP responses with turn-key assertions

 • Help testers update their tests once their specifications modification by The synchronize feature. thus it’s gratuitous to manually update tests when adding new parameters or dynamical the response of the API

 In Oct 2019, Assertible intercalary the Encrypted variables feature, that provides a brand new thanks to store passwords, tokens, and secret knowledge fields. This providing is to enhance API testing security practices.

 12. Rest-Assured

 This source code Java Domain-specific language permits testing REST services additional merely. It is often wont to validate and verify the response of those requests.

 The key features include::

 • Offer a bunch of baked-in functionalities to assist users to proceed with the codeless observe

 • Integrates seamlessly with Serenity automation framework, so users will mix the UI and REST tests in one framework that extracts glorious reports

 • Support BDD Given/When/Then syntax

 • Supports POST, GET, PUT, DELETE, OPTIONS, PATCH, and HEAD requests

 • Users don’t ought to be Associate in Nursing HTTP skilled to utilize this tool

 Version 4.0.0 needed a minimum of Java eight, offered support for Apache Johnzon, and glued several problems with the initial OSGi support. the newest version 4.4.0 is discharged with numerous enhancements and bug fixes.

13. JMeter

Initially, JMeter was created for performance testing, however, it’s ordinarily used for practical API testing.

 The key features include::

 • Cache and offline replay of taking a look at results

 • Automatically work with CSV files, therefore sanctioning the team to make distinctive parameter values for the API tests at speed

 • Able to incorporate the API tests in the CI pipeline due to JMeter and Jenkins integrations

 • Available for each static and dynamic resources performance testing

 The latest unharness JMeter five.4.1 is filled with versatile options and enhancements like new themes, bug fixes, visual illustration of disabled parts, revamped Groovy library, and updated JMeter templates for practical testing. This tool is most fitted for net application performance and cargo testing.

14. Apigee

Apigee could be a cross-cloud API testing tool, enabling users to live and check API performance, support, and build API. Apigee additionally provides PCI, HIPAA, SOC2, and PII for apps. This tool has been named in a veryll|one amongst|one in every of} the leaders within the 2019 Gartner Magic Quadrant for Full Lifecycle API Management fourfold in a row.

 The key features include::

 • Allows style to observe, implement and extend API

 • It is multi-step and high-powered by Javascript

 • Define performance problems by pursuit API traffic, error rate, and time interval

 • Easily produce associate degree API proxy supported open API specifications and deploy it within the cloud

 This tool is intended for digital businesses and therefore the data-rich mobile-driven arthropod genus and apps that power it. Since version four.19.01 in 2019, Apigee provides users a lot of flexibility to manage their arthropod genus with options (e.g., Open API 3.0 support, TLS security, Self-healing with apigee-monit, Virtual host management improvements). Now, the newest version is increased with minor bug fixes and security enhancements. Overall, it’s feature-rich and well recognized by users.

15. POSTMAN

Originally a Chrome browser plugin, mailman extended to associate degree on-premise answer for each raincoat and Windows.

 The key features include::

 • Easy-to-use REST consumer

 • Offer a wealthy interface

 • Available for each automatic and explorative testing

 • Able to run on raincoat, Linux, Windows

 • Provide several integrations like support for Swagger & RAML formats

 • Run, test, document, and observance options

 Users might share the data with the team relaxed as they’ll package up all the requests and expected responses, then send them to their coworkers.

 In version seven.3 of 2020, mailman uses new advanced preferences to assist users neatly organizing the collections and API parts (mock servers, monitors, tests, and documentation) generated from API schemas. Also, you’ll manage your team’s public information and share links to all or any things within the space, like collections, requests, and arthropod genera from mailman app.

16. Ready API

SmartBear provides the ReadyAPI platform for the useful, security, and cargo testing of quiet, SOAP, GraphQL, and alternative internet services.

 In one intuitive platform, you’ll get four powerful tools, API useful testing, API performance testing, API security testing, and API & internet virtualization. This platform can assist you to confirm end-to-end quality for all internet services.

 It provides versatile automation choices for group action API testing into your CI/CD pipeline throughout each build. you’ll be ready to produce comprehensive and data-driven useful API tests.

 Features:

 • ReadyAPI will be integrated into any setting.

 • It encompasses a sensible Assertion feature which will produce bulk assertions against many endpoints quickly.

 • It provides native support for bum, Docker, Jenkins, Azure, etc.

 • It additionally supports Command-line for automatic testing.

 • It supports parallel execution of useful tests and job queuing.

 • It provides options and usefulities for reusing the functional tests and generating realistic load situations.

 • ReadyAPI additionally provides options for removing dependencies throughout testing and development.

17. ACCELQ

ACCELQ is the solely cloud-based continuous testing platform that seamlessly automates API and net testing while not writing one line of code. IT groups of all sizes use ACCELQ to accelerate their testing by automating important aspects of lifecycle like test style, planning, take a look at generation, and execution.

 ACCELQ customers generally save over seventieth of the price concerned within the modification & maintenance efforts in testing, addressing one amongst the key pain points within the business. ACCELQ makes this attainable with AI-powered core to bring self-healing automation amongst different distinctive capabilities.

 Design and User expertise focus is at the guts of ACCELQ’s continuous innovation approach with a relentless effort to accelerate testing and improve delivered Quality for its customers.

 Key Capabilities:

 • Zero code API take a look at Automation on Cloud

 • API and UI take a look at Automation within the same simplified flow

 • API action at law Management, take a look at coming up with, Execution and chase governance

 • Dynamic atmosphere management

 • Chain API Tests for true end-to-end validation

 • straightforward and automatic modification impact analysis of API take a look at suite

 • Regression suite coming up with with necessities chase correlative with business processes

 • Execution chase with full visibility and defect chase integrations

 • Directly correlate Business method and corresponding API for complete coverage

 • Seamless CI/CD and Jira/ALM integration with natural traceability

 • No seller lock, long framework software aligned

18. Swagger.io

The Swagger could be a tool which will assist you through the complete lifecycle of an API. This tool can enable doing a useful, performance, and security testing of API.

 Swagger Inspector helps the developers and QAs to manually validate and explore the genus Apis within the cloud. Load and performance testing is performed through LoadUI professional. It’ll enable you to utilize the useful tests of SoapUI. Swagger provides several open supply tools.

 Features:

 Swagger provides the subsequent options associated with API:

 • API style and development

 • API documentation

 • API Testing

 • API Mocking and Virtualizations

 • API Governance and observance

19. RunScope

An excellent tool for observance and testing API’s. This tool will be used for information validation of API’s to confirm correct information area unit came back. This tool comes with a feature of pursuit and notifying within the case of any API dealing Failure, thus if your application needs payment validation, then this tool will encourage be a decent alternative.

20. Chakram

This tool supports end-to-end take a look at on JSON REST endpoints. This tool additionally supports third-party API testing. This tool may be a good facilitate if you are searching for testing API’s that are still below development. This is often engineered on the Mocha testing framework.

21. Rapise

This tool comes with an intensive feature list that satisfies differing types of testing wants, one amongst them being API testing. This supports testing SOAP internet services further as REST internet services. additionally, it permits testing different types of DLL API’s starting from managed i.e. written mistreatment .NET framework to unmanaged written mistreatment native Intel x eighty six codes.

22. API Science

API Science, a superb API observance tool, comes with a feature to watch Internal yet as External API’s. This tool lets the user apprehend if any API ever goes down, thus necessary action will be taken to bring it copy. vital options embody wonderful API medical specialty, easy dashboard, alert and notification system, powerful coverage and supports JSON, REST, XML, and Oauth.

23. Quadrillian

It’s a web-based REST JSON API testing tool. It lets user follow a structure by making a project, then a check suite so produce and create/place the check cases. It lets creation & sharing of the check suite mistreatment browser. The tests are often run on the web site or are often downloaded.

24. Ping API

It’s an automatic API testing and monitoring tool. Terribly straightforward to use, lets the user produce a action victimization JavaScript or occasional Script, run tests, and additionally includes a feature wherever tests may be scheduled. For any failures, the user gets notified through email, Slack, and Hipchat.

25. Fiddler

Fiddler may be a free debugging tool from Telerik. This tool is especially wont to monitor the network traffic between a laptop and therefore the net. This works well on any browser, any system, and any platform. It’s additionally one of the simplest security testing tools for net applications as a result of the technique it uses for decrypting HTTPS traffic.

26. WebInject

WebInject could be a free tool used for testing internet applications and internet services. this can be written in Perl language and for running this on any platform, a Perl Interpreter is needed. This tool uses associate degree XML API for making take a look at cases and generates HTML and XML report which has a pass/fail standing, errors, and response times. Overall it’s a decent tool.