18.4
Scalar is a collection of API products for documentation, client generation, API management, requests, and MCP server use.
Free planOpen sourceWebAPILinux
Best API Development Tools in 2026
28.3
HTTPie is an API client for building and testing requests to APIs, HTTP servers, and web services.
Free planOpen sourceWebLinuxmacOS
38.2
SoapUI is an open-source tool for testing REST, SOAP and GraphQL web services.
Free planOpen sourceAPILinuxmacOS
- 4
Bruno
Bruno is a Git-native API client for exploring and testing REST, GraphQL, gRPC, and WebSocket APIs.
Free planOpen sourceAPIExtensionLinuxmacOS8.1From $6 a month - 5
Apidog
Apidog is an API platform for designing, debugging, mocking, testing, and documenting APIs, with GraphQL and SOAP support.
Free planWebAPIExtensionLinux8.0From $9 a month - 6
Beeceptor
Beeceptor is a developer-focused API simulation platform for creating mocks, virtualizing services, testing contracts, and simulating failures.
Free planWebAPILinuxmacOS7.9From $10 a month - 7
Testfully
Testfully is an API testing and monitoring platform with web, desktop and browser extension options.
Free planWebExtensionLinuxmacOS7.8Free plan - 8
Postman
Postman is a platform for designing, testing, distributing, documenting, and monitoring APIs.
Free planWebExtensionLinuxmacOS7.6From $9 a month - 9
ReadyAPI
WebAPILinuxmacOS7.6 - 10
Pact
Pact is a code-first tool for contract testing of HTTP and message integrations.
Free planAPILinuxmacOSSelf-hosted7.5From $115.42 a month - 11
Insomnia
Insomnia is an API collaboration platform for designing, testing, debugging, mocking, and governing APIs.
Free planLinuxmacOSSelf-hostedWindows7.2From $12 a month - 12
Kreya
Kreya is a desktop API client for exploring, testing, and automating API workflows.
Free planLinuxmacOSWindows7.1Free plan - 13
SwaggerHub
SwaggerHub is a toolkit for API design, testing, documentation, and governance.
Free planWebSelf-hosted7.1From $740 a year - 14
Redocly
WebAPIExtension7.0From $10 a month - 15
Requestly
Requestly is a desktop API client with web access for building, organizing, documenting, and testing APIs.
LinuxmacOSWindows7.0From $10 a month - 16
Thunder Client
Thunder Client is a REST API client that runs inside VS Code and JetBrains IDEs.
Free planExtensionLinuxmacOSWindows7.0From $3 a month - 17
Yaak
Yaak is a local-first desktop API client for sending requests, debugging APIs, and organizing work with Git.
Free planLinuxmacOSWindows7.0From $79 a year - 18
Assertible
Assertible tests and monitors APIs, websites, and other HTTP services for uptime, availability, and correct behavior.
Free planWebAPI6.9From $25 a month - 19
HTTP Toolkit
HTTP Toolkit is an open-source tool for debugging, testing, and building with HTTP.
Free planAndroidiOSWebLinux6.9Free plan - 20
Mockoon
Mockoon is a free, open-source tool for designing and running mock APIs locally.
WebAPILinuxmacOS6.8From €10 a month - 21
ReadMe
Free planWeb6.7From $250 a month - 22
OpenAPI Generator
OpenAPI Generator creates API clients, server stubs, and documentation from OpenAPI 2.0 and 3.x documents.
Free planWebLinuxmacOSSelf-hosted6.5Free plan - 23
Bump.sh
Bump.sh is a paid web, API, and self-hosted service for publishing API documentation and providing MCP servers that update with API releases.
WebAPISelf-hosted6.4From $50 a month - 24
Schemathesis
Schemathesis generates property-based tests from OpenAPI and GraphQL schemas to help engineers find API bugs.
Free planLinuxmacOSSelf-hostedWindows6.4Free plan - 25
Stainless
Stainless generates SDKs, documentation, and MCP servers from OpenAPI specifications.
Free planWebLinuxmacOS6.4Free plan