Comparison

Mock Service Worker (MSW) vs Prism

On the evidence we track, Mock Service Worker (MSW) leads this comparison with a composite score of 61/100. Scores are only directly comparable because these tools share a category; the full breakdown and every source is below.

Mock Service Worker (MSW) full profile →Prism full profile →

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★Mock Service Worker (MSW)61

Prism50

Attribute comparison across 2 tools
Attribute	Mock Service Worker (MSW)Leader	Prism
vioscaleAI score	61 / 100high · 79%	50 / 100low · 17%
Pricing
Free tierpricing.free_tier	✓	✓
Modelpricing.model	open_source	open_source
Price levelpricing.price_level	free	free
Transparentpricing.transparent	✓	✓
Integrations
Countintegrations.count	8	1
Security
Gdprsecurity.gdpr	-	✓
Scorecardsecurity.scorecard	6.2	-
Vulnerabilitiessecurity.vulnerabilities	Count: 0 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=npm&package_name=msw&per_page=100 · Last 12m: 0	-
Adoption
Dependent reposadoption.dependent_repos	11,851	-
Github starsadoption.github_stars	18,290	-
Activity
Commits last 30dactivity.commits_last_30d	15	-
Release
Cadence daysrelease.cadence_days	2	-
Historyrelease.history	20 items	-
License
Spdxlicense.spdx	MIT	-
Language
Primarylanguage.primary	TypeScript	-
Market
Availabilitymarket.availability	Available worldwide	Available worldwide
Content
Faqcontent.faq	5 items	6 items

Score

vioscaleAI score

Mock Service Worker (MSW)61 / 100high · 79%

Prism50 / 100low · 17%

Pricing

Free tier

Mock Service Worker (MSW)✓

Prism✓

Model

Mock Service Worker (MSW)open_source

Prismopen_source

Price level

Mock Service Worker (MSW)free

Prismfree

Transparent

Mock Service Worker (MSW)✓

Prism✓

Integrations

Count

Mock Service Worker (MSW)8

Prism1

Security

Gdpr

Mock Service Worker (MSW)–

Prism✓

Scorecard

Mock Service Worker (MSW)6.2

Prism–

Vulnerabilities

Mock Service Worker (MSW)Count: 0 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=npm&package_name=msw&per_page=100 · Last 12m: 0

Prism–

Adoption

Dependent repos

Mock Service Worker (MSW)11,851

Prism–

Github stars

Mock Service Worker (MSW)18,290

Prism–

Activity

Commits last 30d

Mock Service Worker (MSW)15

Prism–

Release

Cadence days

Mock Service Worker (MSW)2

Prism–

History

Mock Service Worker (MSW)20 items

Prism–

License

Spdx

Mock Service Worker (MSW)MIT

Prism–

Language

Primary

Mock Service Worker (MSW)TypeScript

Prism–

Market

Availability

Mock Service Worker (MSW)Available worldwide

PrismAvailable worldwide

Content

Faq

Mock Service Worker (MSW)5 items

Prism6 items

Capabilities

Feature-by-feature on the axes that matter for api mocking. “-” means undocumented, not absent.

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

Capabilities

Mocking mode

Mock Service Worker (MSW)Dynamic templating

PrismDynamic templating

Stateful scenarios

Mock Service Worker (MSW)✓

Prism-

Fault chaos injection

Mock Service Worker (MSW)-

Prism-

Openapi import

Mock Service Worker (MSW)✓

Prism✓

Proxy passthrough

Mock Service Worker (MSW)-

Prism✓

Admin API

Mock Service Worker (MSW)-

Prism-

Deployment

Mock Service Worker (MSW)Embedded library

PrismCLI binary

Legacy protocol virtualization

Mock Service Worker (MSW)-

Prism-

Collaboration sharing

Mock Service Worker (MSW)-

Prism✓

Ci cd integration

Mock Service Worker (MSW)✓

Prism✓

Open source

Mock Service Worker (MSW)✓

Prism✓

Market segment

Mock Service Worker (MSW)Dev tool

PrismDev tool

Pricing model

Mock Service Worker (MSW)Open source

PrismOpen source

What each one is

The product in its own terms, so the numbers below have context.

Mock Service Worker (MSW)

Leader

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.

Independently observed

Prism

Stoplight is a design-first API platform that enables teams to collaboratively design APIs, generate interactive documentation, and create mock API servers with built-in validation. It supports multiple API standards including OpenAPI, AsyncAPI, and Arazzo.

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

Mock Service Worker (MSW)

Leader

Open sourceFree tier

Free and open source

as of 2026-10-14verify ↗

Prism

from $11/moHybridFree tier14-day trial

Free open-source version. Stoplight SaaS: from $44/month (Basic). Free 14-day trial.

FreeFree
- API editor
- OpenAPI/JSON schema visual designer
- Code-based editing
- Local mock servers
- API console
- +2 more
Basic$44/month (annually) or $56/month; includes 3 users, $11 per additional user
- OpenAPI/JSON schema visual designer
- Interactive docs
- Instant mock servers
- Code-based editing
- Schema reuse
- +6 more
Startup$113/month (annually) or $147/month; includes 8 users, $11 per additional user
- All Basic features
- Private projects
- Multi-branch support
- Custom domains, theming and favicon
- Google Analytics integration
- +3 more
Pro Team$362/month (annually) or $453/month; includes 15 users, $22 per additional user
- All Startup features
- Shared style guides
- Workspace groups
- Remove Stoplight branding
- Self-hosted Git providers
- +6 more
EnterpriseContact sales
- All Pro Team features
- Custom payment terms
- Invoicing
- Priority support

as of 2026-08-17verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platform and deployment support comparison
Supports	Mock Service Worker (MSW)	Prism
WebPlatforms	✓	✓
CLIPlatforms	✓	✗
Cloud / SaaSDeployment	-	✓
Self-hostedDeployment	-	✓

Platforms

Web

Mock Service Worker (MSW)✓

Prism✓

CLI

Mock Service Worker (MSW)✓

Prism✗

Deployment

Cloud / SaaS

Mock Service Worker (MSW)–

Prism✓

Self-hosted

Mock Service Worker (MSW)–

Prism✓

Integrations

What each product connects to. Counts come from the vendor's own integration directory where one exists.

Mock Service Worker (MSW)

Leader

10 total

Vitest
Playwright
Storybook
React Native
Express
fetch
axios
react-query
Hono
Fastify

Independently observed

Prism

9 total

GitHub
GitLab
Azure DevOps
Bitbucket
LDAP
SAML SSO
Google Analytics
OpenAPI
Postman

Independently observed

Still deciding?

Mock Service Worker (MSW) or Prism: which one depends on you

A composite score cannot know your constraints. Describe them and both get re-weighted against what you actually need, with the evidence behind every position.

Free to run, no account needed to start. How the evaluation works

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.