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Best API Clients in 2026 — page 2

  1. 26

    RESTK

    Free plan MacWindows

    RESTK offers a broad free API client with scripting, imports, workspace choices and team roles. Its platform support currently excludes Linux, and formal SLA coverage is not available.

    7.0 Free plan Visit site
  2. 27

    curl

    by curl
    Free plan AndroidiPhoneLinux+2

    curl provides broad protocol coverage and detailed transfer controls across major operating systems. Its command-line tool and libcurl library support both direct scripting and embedded software use.

    7.0 Free plan Visit site
  3. 28

    Posting

    Free plan LinuxMacWindows

    Posting offers a scriptable, keyboard-focused API client with local, versionable request files. Missing WebSockets and automated test runs limit its coverage for some testing workflows.

    6.9 Open source Visit site
  4. 29

    WhoisJSON API

    Free plan APILinuxMac+2

    WhoisJSON API combines broad domain intelligence coverage with documented clients and a free starting plan. Check request limits and cache behavior when your application needs frequent fresh results.

    6.9 Free plan · paid from $10/mo Visit site
  5. 30

    GraphiQL

    Free plan Self-hostedWeb

    GraphiQL combines browser-based GraphQL editing with an embeddable React package and several transport options.

    6.8 Free plan Visit site
  6. 31

    Refit

    Free plan APIWebWindows

    Refit provides a free, attribute-driven way to generate HTTP clients while leaving core client and serialization choices in the application.

    6.7 Free plan Visit site
  7. 32

    HTTP Prompt

    Free plan LinuxMacWindows

    HTTP Prompt offers a broad interactive request workflow with OpenAPI assistance, local sessions, and shell integration at no listed cost.

    6.6 Open source Visit site
  8. 33

    ReadyAPI

    Free trial APILinuxMac+3

    ReadyAPI covers several API testing needs, with distinct plans for testing, performance, and virtualization.

    6.5 14-day trial Visit site
  9. 34

    nasapower

    Free plan API

    nasapower provides a focused R interface for requesting NASA POWER data in several time formats and geographic scopes.

    6.5 Free plan Visit site
  10. 35

    Requestly

    Free trial LinuxMacWindows

    Requestly combines broad protocol support, testing, documentation, and collaboration across desktop and web.

    6.3 From $10/user/mo (annual) · 30-day trial Visit site
  11. 36

    SPARQLWrapper

    Free plan APILinux

    SPARQLWrapper provides broad query, output, conversion, and authentication support for Python SPARQL work. Manual query-type handling is the main stated limitation.

    6.3 Free plan Visit site
  12. 37

    NativeRest

    by NativeRest
    Free trial LinuxMacWindows

    NativeRest offers broad API testing, scripting, import, and workspace options across desktop platforms.

    5.7 From $199 · 7-day trial Visit site
  13. 38

    Karve

    Free trial Windows

    Karve provides a Windows desktop license with a 15-day trial and included v1.x updates.

    5.4 From $39.99 · 15-day trial Visit site