# json-server vs Mock Service Worker (MSW)

**Leader by Vioscale score:** json-server

| Attribute | json-server | Mock Service Worker (MSW) |
|---|---|---|
| **Vioscale score** | 81.6 (57% (medium)) | 58.1 (81% (high)) |
| adoption.dependent_repos | 85,674 | 11,851 |
| adoption.github_stars | 75,690 | 18,168 |
| 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 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. |
| integrations.count | - | 8 |
| integrations.list | - | `[{"name":"Vitest"},{"name":"Playwright"},{"name":"Storybook"},{"name":"React Native"},{"name":"Express"},{"name":"fetch"},{"name":"axios"},{"name":"react-query"}]` |
| 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","freeTier":true,"sourceUrl":"https://mswjs.io","retrievedAt":"2026-08-17T21:32:17.412Z"}` |
| pricing.free_tier | yes | yes |
| pricing.model | commercial | commercial |
| pricing.price_level | free | free |
| pricing.transparent | 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/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"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.12.14","date":"2026-03-21T01:42:04Z","type":"stable","version":"v2.12.14"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.12.13","date":"2026-03-17T11:36:51Z","type":"stable","version":"v2.12.13"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.12.12","date":"2026-03-17T01:42:36Z","type":"stable","version":"v2.12.12"},{"url":"https://github.com/mswjs/msw/releases/tag/v2.12.11","date":"2026-03-15T19:07:45Z","type":"stable","version":"v2.12.11"}]` |
| security.scorecard | 3.6 | 6.2 |
| 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 | - | - |
| Stateful scenarios | - | - |
| Fault chaos injection | - | - |
| Openapi import | - | - |
| Proxy passthrough | - | - |
| Admin API | - | - |
| Deployment | - | - |
| Legacy protocol virtualization | - | - |
| Collaboration sharing | - | - |
| Ci cd integration | - | - |
| Open source | - | - |
| Market segment | - | - |
| Pricing model | - | - |

*Source: Vioscale. Generated 2026-09-01T16:30:21.008Z. "-" = undocumented, not absent.*