Mockfly vs Mockoon

Mockfly provides hosted mock REST API endpoints for teams building or testing before a backend is ready. An endpoint can return JSON, XML, or files such as PDFs and CSVs, and can select among several responses using rules tied to incoming requests. Mock data can use Faker.js templates or AI-generated JSON. Projects can start from OpenAPI, Swagger, Postman collection, or HAR imports; a Chrome extension can capture browser requests and add selected endpoints. Teams can share and edit mocks, inspect request logs, and review response-body history. For offline work, the mockfly-cli npm package pulls projects to serve locally. A public REST API and MCP server support programmatic mock creation and editing. Mockfly lists API, extension, Linux, self-hosted, and web platforms, and supports REST and WebSocket. The free Starter plan allows 500 requests per day, one project, four endpoints, and two responses per endpoint. Pro costs €15 a month; Team costs €49 a month; Company is listed from €199 a month.

Mockoon is a free, open-source tool for designing and running mock APIs locally. It supports OpenAPI and can fit into existing applications and API design workflows. Mock behavior can use dynamic templating, rule matching, JSON databases, proxy mode, webhooks, and TLS. The tool can record requests and responses from a real API to create mocks, and it supports proxying and integration testing. The open-source version permits unlimited mock APIs and routes, including parallel runs. Its CLI can run mocks in headless automated environments such as CI, GitHub Actions, and Docker; mocks can also run in serverless environments including AWS Lambda and GCP/Firebase Functions. The desktop app stores mocks locally, works offline without an account, and reports that mock content and request data are not sent to Mockoon. Pro adds real-time team collaboration, synchronized mocks, and deployment management on private infrastructure; it can be self-hosted on-premises, in a private cloud, or on isolated or air-gapped networks. Team is listed at €10 a month, billed annually at €120/license/year, tax excluded. Eligible companies can request one 14-day self-hosted Pro trial with five license slots using a verified work email, without a payment method.