# json-server vs Mock Service Worker (MSW)

| Attribute | json-server | Mock Service Worker (MSW) |
|---|---|---|
| **vioscaleAI score** | 62.5 (64% (medium)) | 60.5 (79% (high)) |
| activity.commits_last_30d | - | 15 |
| adoption.dependent_repos | 85,674 | 11,851 |
| adoption.github_stars | 75,731 | 18,290 |
| content.faq | `[{"answer":"An open-source tool that generates a full-featured REST API server from a JSON or JSON5 file, enabling rapid prototyping and testing without backend development. It is indexed under API Mocking.","source":"https://github.com/pricing","question":"What is json-server?","confidence":0.6},{"answer":"json-server is open source, so it can be self-hosted and used at no licence cost. It is released under the MIT licence. Pricing changes often, so verify at source before relying on it.","source":"https://github.com/pricing","question":"Is json-server free to use?","confidence":0.6},{"answer":"json-server supports the web and a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://github.com/pricing","question":"What platforms does json-server support?","confidence":0.6},{"answer":"Yes. json-server can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://github.com/pricing","question":"Can json-server be self-hosted?","confidence":0.6},{"answer":"Yes. json-server is published under the MIT licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.","source":"https://github.com/typicode/json-server","question":"Is json-server open source?","confidence":0.95}]` | `[{"answer":"An API mocking library that intercepts network requests at the browser and Node.js levels, allowing consistent mock responses across testing frameworks, tools, and applications without requiring client-specific stubs or configuration. It is indexed under API Mocking.","source":"https://mswjs.io","question":"What is Mock Service Worker (MSW)?","confidence":0.6},{"answer":"Mock Service Worker (MSW) is open source, so it can be self-hosted and used at no licence cost. It is released under the MIT licence. Pricing changes often, so verify at source before relying on it.","source":"https://mswjs.io","question":"Is Mock Service Worker (MSW) free to use?","confidence":0.6},{"answer":"Mock Service Worker (MSW) supports the web and a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://mswjs.io","question":"What platforms does Mock Service Worker (MSW) support?","confidence":0.6},{"answer":"We have confirmed 8 integrations for Mock Service Worker (MSW), including Vitest, Playwright, Storybook, React Native, Express, fetch, axios and react-query. This is what we could verify from public sources, so the vendor may support others we have not indexed.","source":"https://mswjs.io","question":"What does Mock Service Worker (MSW) integrate with?","confidence":0.6},{"answer":"Yes. Mock Service Worker (MSW) is published under the MIT licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.","source":"https://github.com/mswjs/msw","question":"Is Mock Service Worker (MSW) open source?","confidence":0.95}]` |
| deployment.options | `{"self_hosted":true}` | - |
| description.long | An open-source tool that generates a full-featured REST API server from a JSON or JSON5 file, enabling rapid prototyping and testing without backend development. | An open-source API mocking library that uses the Service Worker API to intercept network requests in browsers and Node.js, enabling developers to mock REST, GraphQL, and WebSocket APIs for testing and development without modifying application code. |
| features.capabilities | `{"deployment":"cli_binary","open_source":true,"mocking_mode":"static","pricing_model":"open_source","market_segment":"dev-tool"}` | `{"deployment":"embedded_library","open_source":true,"mocking_mode":"dynamic_templating","pricing_model":"open_source","market_segment":"dev-tool","openapi_import":true,"ci_cd_integration":true,"stateful_scenarios":true}` |
| integrations.count | - | 8 |
| integrations.list | - | `[{"name":"Vitest"},{"name":"Playwright"},{"name":"Storybook"},{"name":"React Native"},{"name":"Express"},{"name":"fetch"},{"name":"axios"},{"name":"react-query"},{"name":"Hono","native":true},{"name":"Fastify","native":true}]` |
| language.primary | JavaScript | TypeScript |
| license.spdx | MIT | MIT |
| market.availability | - | `{"primaryMarkets":[],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` |
| platform.support | `{"cli":true,"web":true}` | `{"cli":true,"web":true}` |
| pricing | `{"type":"open_source","summary":"Free, open-source","freeTier":true,"sourceUrl":"https://github.com/pricing","retrievedAt":"2026-08-17T21:30:41.016Z"}` | `{"type":"open_source","summary":"Free and open source","freeTier":true,"sourceUrl":"https://mswjs.io","retrievedAt":"2026-10-14T21:33:51.343Z"}` |
| pricing.free_tier | yes | yes |
| pricing.model | open_source | open_source |
| pricing.price_level | free | free |
| pricing.transparent | yes | yes |
| release.cadence_days | 6 | 2 |
| release.history | `[{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.15","date":"2026-03-23T19:40:05Z","type":"stable","version":"v1.0.0-beta.15"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.14","date":"2026-03-20T15:15:06Z","type":"stable","version":"v1.0.0-beta.14"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.13","date":"2026-03-13T00:36:40Z","type":"stable","version":"v1.0.0-beta.13"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.12","date":"2026-02-28T00:44:28Z","type":"stable","version":"v1.0.0-beta.12"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.10","date":"2026-02-26T22:49:44Z","type":"stable","version":"v1.0.0-beta.10"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.9","date":"2026-02-19T23:37:59Z","type":"stable","version":"v1.0.0-beta.9"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.8","date":"2026-02-19T23:08:52Z","type":"stable","version":"v1.0.0-beta.8"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.7","date":"2026-02-19T22:46:20Z","type":"stable","version":"v1.0.0-beta.7"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.6","date":"2026-02-14T22:48:17Z","type":"stable","version":"v1.0.0-beta.6"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.5","date":"2026-01-22T09:26:14Z","type":"stable","version":"v1.0.0-beta.5"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.4","date":"2026-01-21T22:57:31Z","type":"stable","version":"v1.0.0-beta.4"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.3","date":"2024-09-24T13:21:29Z","type":"stable","version":"v1.0.0-beta.3"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.2","date":"2024-08-19T13:12:26Z","type":"stable","version":"v1.0.0-beta.2"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.1","date":"2024-06-04T10:10:16Z","type":"stable","version":"v1.0.0-beta.1"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-beta.0","date":"2024-05-13T13:29:13Z","type":"stable","version":"v1.0.0-beta.0"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-alpha.23","date":"2024-01-26T17:34:24Z","type":"stable","version":"v1.0.0-alpha.23"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-alpha.22","date":"2024-01-22T15:08:04Z","type":"stable","version":"v1.0.0-alpha.22"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-alpha.21","date":"2024-01-13T22:50:00Z","type":"stable","version":"v1.0.0-alpha.21"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-alpha.20","date":"2024-01-13T01:43:42Z","type":"stable","version":"v1.0.0-alpha.20"},{"url":"https://github.com/typicode/json-server/releases/tag/v1.0.0-alpha.19","date":"2024-01-12T00:10:55Z","type":"stable","version":"v1.0.0-alpha.19"}]` | `[{"url":"https://github.com/mswjs/msw/releases/tag/v3.0.3","date":"2026-10-10T01:37:25Z","type":"stable","version":"v3.0.3"},{"url":"https://github.com/mswjs/msw/releases/tag/v3.0.2","date":"2026-10-03T01:30:56Z","type":"stable","version":"v3.0.2"},{"url":"https://github.com/mswjs/msw/releases/tag/v3.0.1","date":"2026-09-30T12:36:57Z","type":"stable","version":"v3.0.1"},{"url":"https://github.com/mswjs/msw/releases/tag/v3.0.0","date":"2026-09-28T15:40:54Z","type":"stable","version":"v3.0.0"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.15.0","date":"2026-07-08T01:43:13Z","type":"stable","version":"v2.15.0"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.14.7","date":"2026-07-07T18:24:49Z","type":"stable","version":"v2.14.7"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.14.6","date":"2026-05-11T09:41:54Z","type":"stable","version":"v2.14.6"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.14.5","date":"2026-05-08T01:51:55Z","type":"stable","version":"v2.14.5"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.14.4","date":"2026-05-07T12:26:03Z","type":"stable","version":"v2.14.4"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.14.3","date":"2026-05-04T17:14:11Z","type":"stable","version":"v2.14.3"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.14.2","date":"2026-04-29T15:37:39Z","type":"stable","version":"v2.14.2"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.14.1","date":"2026-04-29T15:11:07Z","type":"stable","version":"v2.14.1"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.14.0","date":"2026-04-29T14:12:53Z","type":"stable","version":"v2.14.0"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.13.6","date":"2026-04-24T15:53:44Z","type":"stable","version":"v2.13.6"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.13.5","date":"2026-04-23T01:46:05Z","type":"stable","version":"v2.13.5"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.13.4","date":"2026-04-16T16:25:47Z","type":"stable","version":"v2.13.4"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.13.3","date":"2026-04-14T01:44:10Z","type":"stable","version":"v2.13.3"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.13.2","date":"2026-04-08T11:18:18Z","type":"stable","version":"v2.13.2"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.13.1","date":"2026-04-07T18:14:15Z","type":"stable","version":"v2.13.1"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.13.0","date":"2026-04-06T12:37:48Z","type":"stable","version":"v2.13.0"}]` |
| security.scorecard | 3.6 | 6.2 |
| security.trust_center | https://github.com/security | - |
| security.vulnerabilities | `{"count":0,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=npm&package_name=json-server&per_page=100","last_12m":0,"max_severity":null}` | `{"count":0,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=npm&package_name=msw&per_page=100","last_12m":0,"max_severity":null}` |

## Capabilities (API Mocking)

| Capability | json-server | Mock Service Worker (MSW) |
|---|:--:|:--:|
| **Capabilities** |  |  |
| Mocking mode | Static | Dynamic templating |
| Stateful scenarios | - | ✓ |
| Fault chaos injection | - | - |
| Openapi import | - | ✓ |
| Proxy passthrough | - | - |
| Admin API | - | - |
| Deployment | CLI binary | Embedded library |
| Legacy protocol virtualization | - | - |
| Collaboration sharing | - | - |
| Ci cd integration | - | ✓ |
| Open source | ✓ | ✓ |
| Market segment | Dev tool | Dev tool |
| Pricing model | Open source | Open source |

*Source: vioscaleAI. Generated 2026-10-16T19:19:00.452Z. "-" = undocumented, not absent.*