Compare the Top Free API Testing Tools as of April 2025

What are Free API Testing Tools?

API testing software is used to test and validate the functionality, performance, security, and reliability of Application Programming Interfaces (APIs). These tools help ensure that APIs perform as expected under various conditions and meet the required business and technical requirements. Features typically include automated testing, request/response validation, load testing, security testing (e.g., for vulnerabilities and authentication), and performance testing. API testing software often supports integration with continuous integration/continuous deployment (CI/CD) pipelines to facilitate automated testing as part of the software development lifecycle. Compare and read user reviews of the best Free API Testing tools currently available using the table below. This list is updated regularly.

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    Cerberus Testing

    Cerberus Testing

    Cerberus Testing

    Cerberus Testing is a low-code software testing automation enabling continuous testing at scale. Using the solution you can remove years of implementing an internal testing framework. The product enables you to quickly iterate through your testing lifecycle, from test repository, execution, reporting and analytics. The solution allows the collaboration of the teams from the use-cases definition to the test case execution on the variety of browsers, devices, apps and APIs. You can leverage your own or external robots infrastructure to execute your test at scale, enabling you to focus on your business value. It supports various integrations for speed of implementation such as Jenkins, Bitbucket, Slack, Kafka. It is available and maintained in open-source by various digital and retail players such as La Redoute, Decathlon, Adeo, and Norauto.
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    Starting Price: €0
  • 2
    API Tester

    API Tester

    API Tester

    API Tester is a completely free mobile app available on iOS, Android, macOS, and watchOS. It is a functional API testing tool that allows users to complete compound tasks on any device. - Test any API on the go: REST, GraphQL, WebSocket, SOAP, JSON RPC, XML, HTTP, HTTPS. - GET, POST, PUT, PATCH, DELETE, etc. HTTP request methods are supported. - Perform the API calls with any kind of request data encoding and transfer type. - Import collections from Swagger, Postman, and YAML, or import requests using cURL, as well as export created requests via link or cURL. - Use a powerful GraphQL editor with full-scale experience. - WebSocket testing tool is available: handles connection and message exchange via WS or WSS. The API Tester mobile app allows you to get the job away from your workstation. Save time, work from anywhere!
    Starting Price: Completely free
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    ZAPTEST

    ZAPTEST

    ZAPTEST Inc.

    ZAPTEST is a leading Free and Enterprise software test automation and RPA tool. Offerings include Computer Vision technology that allows for Cross-Platform digital interface automation for UI, API, Load testing, and RPA in a seamless process. Combine that with our 1SCRIPT methodology, seamless automation, parallel execution, and unlimited licenses– you get an efficient testing suite that generates up to 10X ROI. We promise that if you can perform a procedure via any digital interface (live application or mockup) manually, ZAPTEST can automate this procedure As-Is! With ZAPTEST’s Enterprise Solution subscription program, you receive unlimited licenses across the entire organization. Regardless of whether your automation needs increase, your cost remains fixed. FARM allows ZAPTEST users to manage all of their devices so you can remotely control cross-environments and projects from any location. ZAPTEST uses many practical applications to enhance its software testing software capabilities
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    Treblle

    Treblle

    Treblle

    Treblle: A lightweight SDK for accelerated REST-based API development, see metadata for every API request with real-time API traffic monitoring, get powerful analytics and API governance features alongside API automated docs, and automated API security audits for every single request. Simplify workflows, enhance security with support for 18+ languages and frameworks for seamless integration. Empower your teams to build, ship, and maintain APIs faster.
    Starting Price: $99 per month
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    BlazeMeter

    BlazeMeter

    BlazeMeter

    BlazeMeter’s open-source based, enterprise ready platform unifies all the functionality you need to shift testing left - and right. Use our intuitive UI to create tests or reuse your existing scripts and run them at scale as part of your continuous testing strategy. Test and generate detailed reporting and see historic trends. Spend more time innovating & less time maintaining your toolchain. Continuous testing is key to delivering with quality, volume, and velocity. But integrating, maintaining, learning and switching between multiple tools wastes valuable time and resources. BlazeMeter makes it easy with a super intuitive platform that does it all. BlazeMeter delivers complete shift left testing, so you can wow the marketplace with innovation. BlazeMeter provides all the components you need for shift left continuous testing. Work with CLIs, APIs, UI, open source tools, and more. Save HUGE time with setup, maintenance, learning, and day to day use.
    Starting Price: $149 per month
  • 6
    Eggplant

    Eggplant

    Keysight Technologies

    At Eggplant we empower organizations to create amazing digital experiences. We help businesses to test, monitor and analyze their end-to-end customer experience and continuously improve their business outcomes. Companies worldwide use Eggplant to surpass competitors, boost productivity, and delight customers. How? By dramatically enhancing the quality, responsiveness, and performance of their software applications across different interfaces, platforms, browsers, and devices - including mobile, IoT, and desktop — in agile, DevOps, and innovative application and data environments. As software release cycles accelerate, manual testing can't keep up. AI automatically discovers user journeys, hunts for bugs and performs image-based UI tests from the user POV. Build better software with fast, broad, accurate AI-powered testing. To keep up with DevOps, continuous testing is key, streamlining development and automating the testing process.
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