Testing & Mocking
Mock servers, contract tests and load tests.
All testing & mocking tools
16- ArtilleryA load testing toolkit with YAML scenarios and JavaScript hooks, HTTP, WebSocket, Socket.IO and gRPC support, Playwright browser tests, and distributed runs on AWS Lambda or Fargate. Core is MPL-2.0.Open source
- GatlingA load testing tool with simulations written as code in Java, Kotlin, Scala, JavaScript or TypeScript. The Community Edition is Apache-2.0; Enterprise Edition adds managed load generation and team features.Open source
- Grafana k6A developer-centric load and performance testing tool scripted in JavaScript and executed in Go.Open source
- HurlA command-line tool from Orange that runs and tests HTTP requests written in a plain-text format, with captures, assertions and CI reports.Open source
- KarateAn open-source test framework from Karate Labs that combines API tests, mocks, performance tests and UI automation in a single readable DSL on the JVM.Freemium
- MicrocksA CNCF open-source platform that turns OpenAPI, AsyncAPI, gRPC, GraphQL, Postman and SoapUI artifacts into live mocks and contract tests.Open source
- MockoonAn easy-to-use local desktop mock server generator featuring a graphical interface.Freemium
- NewmanA command-line collection runner for Postman, allowing tests to be integrated directly into CI/CD pipelines.Open source
- OpticAn OpenAPI diffing, linting and breaking-change tool whose repository was archived in January 2026 after Optic Labs joined Atlassian.Open source
- PactA consumer-driven contract testing framework that lets services verify their integrations without spinning up full end-to-end environments.Open source
- PostmanA comprehensive API platform for building, testing, organizing, and collaborating on HTTP requests.Freemium
- Prism (Stoplight)An open-source mock server that parses OpenAPI specifications and runs mock API endpoints.Open source
- REST AssuredAn open-source Java DSL for testing HTTP APIs with given/when/then syntax, JSON and XML path assertions, and JSON Schema validation.Open source
- SchemathesisA property-based API testing tool that generates thousands of requests from an OpenAPI or GraphQL schema and checks every response against it.Open source
- SoapUIA functional testing application for SOAP and REST APIs, designed for testing complex enterprise integrations.Freemium
- WireMockA simulator for HTTP-based APIs, enabling developers to mock downstream dependencies in integration tests.Open source
