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Best API Testing Tools in 2026

API testing tools help you check how APIs behave, validate contracts, and fit tests into development workflows. Compared on CI/CD integration and contract testing, the entries also differ in GraphQL and SOAP support, mock servers, and scheduled runs. Consider which protocols and test workflows matter for the APIs you maintain, then look at included requests, free-plan availability, and paid-from pricing. Apidog, Postman, and Bruno are among the options shown, alongside Hoppscotch and Insomnia. The listed criteria give you a practical basis for matching capabilities to your testing needs.

  1. 1

    Bruno

    Free plan Open source APIExtensionLinux+3

    Bruno pairs API testing and automation with Git-friendly plain-text collections and companion tools.

    9.2 Free plan · paid from $6/user/mo (annual) · 14-day trial Visit site
  2. 2

    HTTPie

    Free plan Open source LinuxMacWeb+1

    HTTPie offers command-line API testing alongside a graphical app for desktop and web. The CLI plan is open-source, while the Desktop and Web plan is in public beta; both are listed as free.

    9.1 Free plan Visit site
  3. 3

    Karate

    Free plan Open source APIExtensionLinux+3

    Karate offers a free framework spanning API, UI, mock, and performance testing, with paid plans for additional IDE and client features.

    9.0 Free plan · paid from $100/user/yr Visit site
  4. 4

    SoapUI

    Free plan Open source APILinuxMac+2

    SoapUI Open Source offers API testing, mocking, and command-line automation across major listed protocols.

    8.6 Free plan Visit site
  5. 5

    Apidog

    Free plan APIExtensionLinux+4

    Apidog combines API design, testing, mocking, and documentation with specification-driven workflows and deployment choices. Check the plan details and database limits against your team's requirements.

    7.7 Free plan · paid from $9/user/mo (annual) · 14-day trial Visit site
  6. 6

    EvoMaster

    Free plan APILinuxMac+2

    EvoMaster provides free fuzz-based test generation across several API types and programming languages.

    7.6 Free plan Visit site
  7. 7

    EvoMaster

    Free plan APILinuxMac+2

    EvoMaster offers free automated test generation across several API types, with both black-box and JVM-focused white-box modes.

    7.6 Free plan Visit site
  8. 8

    Hoppscotch

    Free plan APILinuxMac+3

    Hoppscotch covers API testing and collaboration, with a free tier and paid team and enterprise plans. Compare the listed plan details with the collaboration and access controls your team needs.

    7.5 Free plan · paid from $6/user/mo (annual) Visit site
  9. 9

    Apiary

    Free plan APIWeb

    Apiary links API descriptions with mock responses, documentation, and automated response checks.

    7.4 Free plan Visit site
  10. 10

    Assertible

    Free plan APIWeb

    Choose Assertible if you need HTTP service checks, deployment smoke tests, or API test synchronization with common specification formats and Postman collections.

    7.4 Free plan · paid from $25/mo Visit site
  11. 11

    Hurl

    Free plan LinuxMacSelf-hosted+1

    Hurl combines request workflows, response assertions, and CI reporting in a free command-line tool. Check the listed Linux and Windows requirements before choosing an installation option.

    7.4 Free plan Visit site
  12. 12

    Insomnia

    Free plan LinuxMacSelf-hosted+1

    Insomnia covers API design and client workflows alongside mocking, CI/CD execution, and team collaboration.

    7.4 Free plan · paid from $12/user/mo · 14-day trial Visit site
  13. 13

    Keploy

    Free plan APIExtensionLinux+4

    Choose Keploy if you want to turn captured application traffic into regression tests and dependency sandboxes, with free local and Playground options.

    7.4 Free plan · paid from $19/user/mo Visit site
  14. 14

    Pact

    Free plan APILinuxMac+2

    Pact focuses on contract-based integration checks, with tools for HTTP, messaging and deployment compatibility workflows.

    7.3 Free plan Visit site
  15. 15

    PactFlow

    Free plan APILinuxSelf-hosted+1

    Pick PactFlow if your team needs a managed broker for Pact or OpenAPI contract testing, especially when you want pull request checks and automation options.

    7.3 Free plan · paid from $115.42/mo (annual) · 14-day trial Visit site
  16. 16

    Citrus

    Free plan Linux

    Choose Citrus for Linux-based integration testing across messaging endpoints and microservices, particularly when message validation and flexible test logic matter.

    7.2 Free plan Visit site
  17. 17

    Kreya

    by Kreya
    Free plan LinuxMacWindows

    Kreya combines broad protocol support with scripted and snapshot testing, imports, and CI/CD use.

    7.2 Free plan · paid from $5/user/mo · 10-day trial Visit site
  18. 18

    Postman

    by Postman
    Free plan ExtensionLinuxMac+2

    Postman combines API creation, testing, documentation, and monitoring in one platform, with a free plan and paid options. Check plan availability and the annual billing terms before choosing a tier.

    7.2 Free plan · paid from $9/mo (annual) Visit site
  19. 19

    Schemathesis

    Free plan LinuxMacSelf-hosted+1

    Schemathesis provides schema-based API testing with adaptive and stateful workflows, authentication options, and CI/CD integrations.

    7.1 Free plan Visit site
  20. 20

    HttpMaster

    Free plan Windows

    HttpMaster offers request chaining, validation, and command-line execution in a free Windows tool. It can send SOAP methods over HTTP, but lacks WSDL parsing.

    7.0 Free plan Visit site
  21. 21

    RESTest

    Free plan LinuxSelf-hostedWindows

    Choose RESTest if you need OpenAPI-based REST API checks that can run without source access and provide repeatable fault requests.

    7.0 Open source Visit site
  22. 22

    Thunder Client

    by Thunder Client
    Free plan ExtensionLinuxMac+1

    Choose Thunder Client if you want an API client inside your IDE, with local data storage and graphical response validation.

    6.9 Free plan · paid from $3/user/mo (annual) · 14-day trial Visit site
  23. 23

    Frisby.js

    Free plan API

    Frisby.js combines HTTP helpers, response assertions, schema checks, and Jest execution for REST API testing. Its free BSD-licensed package fits projects that want customizable JavaScript API tests.

    6.8 Open source Visit site
  24. 24

    PactumJS

    Free plan API

    PactumJS covers several API testing layers and can also serve as a mock server, while fitting into existing test-runner workflows.

    6.8 Free plan Visit site
  25. 25

    RestTestGen

    Free plan LinuxSelf-hosted

    RestTestGen provides broad API test-generation and analysis options without a software charge.

    6.8 Free plan Visit site

#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price

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