Mock Service Worker vs Mockzilla
Mock Service Worker
mswjs.ioMockzilla
mockzilla.orgSide by side
| Figure | Mock Service Worker | Mockzilla |
|---|---|---|
| Price from | — | $10/mo |
| Free plan | — | Yes |
| Free trial | — | Yes |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| API | — | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 0 | 9 |
| Spec score · API Mocking Tools | 7.1 (#21) | 8.9 (#5) |
| Support | The quick start directs users to a debugging runbook, MSW Discord, and GitHub Discussions for help. | The help documentation says support issues can be opened from a workspace and that contact-form questions receive an email reply. |
| What it does | MSW is an API mocking library for browser and Node.js that intercepts outgoing requests so they can be observed and answered with mocked responses. | Mockzilla converts OpenAPI specifications or plain JSON files into hosted mock APIs with shareable URLs. |
Plans
Mockzilla
- FreeFree
- FreeFree
- Hobby$10 a month
- Hobby$10 a month
- Starter$20 a month
- Starter$20 a month
- Pro$50 a month
- Pro$50 a month
- EnterprisePriced on request
In their own words
Mock Service Worker
Mock Service Worker has no write-up on Specifiction yet; its figures are above.
Mockzilla
Mockzilla turns OpenAPI specifications or plain JSON files into hosted mock APIs for frontend work, integration tests, and demos. It generates responses from OpenAPI schemas and can validate requests against the specification. Users can inject latency or errors at service or endpoint level to exercise retry and fallback behavior. A proxy can forward requests to a real backend while supplying mock responses for routes that backend does not serve. Its GitHub Action creates a mock URL for each pull request, updates it on pushes, and cleans it up when the branch is gone. Mockzilla records request status and timing, and supports replaying individual requests or sets of requests. The CLI is MIT-licensed, works offline, and can run on a laptop or in CI; hosted cloud features are optional. The site also lists a GitHub Action and MCP server, with CLI setup instructions for Claude and Gemini. The Free plan is free, but API access is unavailable and request history lasts two hours. Hobby costs $10 a month. Uploaded content must not contain personally identifiable information, real financial data, health records, credentials, or other sensitive data.