Hoverfly vs Mock Service Worker
Hoverfly
hoverfly.io
Mock Service Worker
mswjs.ioSide by side
| Figure | Hoverfly | Mock Service Worker |
|---|---|---|
| Price from | $10/mo | — |
| Free plan | — | — |
| Free trial | Yes | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| API | Yes | — |
| Self-hosted | Yes | Yes |
| Plans published | 3 | 0 |
| Spec score · API Mocking Tools | 8.5 (#6) | 7.1 (#21) |
| Open source | The underlying Hoverfly framework is open source, has no GUI, and is typically used locally or in a user's own network and infrastructure. | The project describes MSW as open-source and free to try. |
| Protocols | Hoverfly Cloud supports HTTP/S services including REST, SOAP, XML, JSON, and GraphQL. | MSW supports mocking HTTP, GraphQL, Server-Sent Events, and WebSocket APIs. |
| Purpose | Hoverfly Cloud is a hosted API simulation and mocking platform for testing without relying on live API dependencies. | Mock Service Worker (MSW) is an API mocking library for browser and Node.js that intercepts outgoing requests so developers can observe and respond with mocked responses. |
| Support | iOCO offers Hoverfly Cloud team support by email and support portal with a guaranteed response within one business day during 9am–6pm GMT. | The quick start directs users to a debugging runbook, MSW Discord, and GitHub Discussions for help. |
Plans
In their own words
Hoverfly
Hoverfly Cloud is a hosted API simulation and mocking platform for testing without live API dependencies. It handles HTTP/S services including REST, SOAP, XML, JSON, and GraphQL. Users can capture and replay traffic, generate simulations from OpenAPI specifications, and match requests by methods, headers, parameters, and bodies. Simulations can delay responses, inject faults or errors, and modify replies. A command-line interface supports scripted configuration and testing pipelines. Hoverfly and hoverctl binaries run on macOS, Linux, and Windows, while documentation covers Docker and Kubernetes installation. The underlying Hoverfly framework is open source under Apache 2, has no GUI, and is generally run locally or in a user’s infrastructure. Cloud use cases include performance testing, functional testing, and development.
Mock Service Worker
Mock Service Worker has no write-up on Specifiction yet; its figures are above.