Comparison

Mockd vs MSW

Standalone API mocking without service worker limitations

Feature Comparison

Side-by-side comparison of Mockd and Mock Service Worker capabilities.

FeatureMockdMSW
HTTP Mocking Yes Yes
WebSocket Yes No
GraphQL Yes Yes
gRPC Yes No
MQTT Yes No
Standalone Server YesNo (browser/Node only)
Record & Replay Yes No
mTLS Support Yes No
Any Language Yes No
Browser TestingVia proxy Native
CI/CD Ready NativeRequires browser
Built-in Cloud Tunnel Yes No
MCP Server (AI editors)18 tools No
AI Mock Generation4 providers No

Why Choose Mockd Over MSW?

No Service Worker Required

Mockd runs as a standalone server. No browser context needed, no service worker registration, no HTTPS requirements. Works everywhere.

Any Language, Any Framework

MSW is JavaScript-only. Mockd works with Python, Go, Java, Rust, Ruby - any language that can make HTTP requests. One mock server for your entire stack.

7 Protocols, Not Just HTTP

Mock WebSocket connections, gRPC services, MQTT brokers, SSE streams, and SOAP endpoints. MSW focuses on HTTP/GraphQL only.

CI/CD Without Headless Browsers

Run your integration tests in CI without spinning up Playwright or Puppeteer. Mockd is a simple binary that starts in milliseconds.

Record Real Traffic

Proxy production or staging APIs, record real responses, then replay them in tests. MSW requires manual mock definition.

Enterprise Security

mTLS authentication, audit logging, RBAC. Share mock servers across teams with proper access control.

When to Use Each Tool

Both tools have their strengths. Here's when to choose each one.

Use MSW for

  • Browser-first unit testing with Jest or Vitest
  • Frontend component tests in isolation
  • Storybook integration for UI development
  • Quick prototyping in browser dev tools

Use Mockd for

  • Backend and API integration testing
  • Multi-protocol mocking (WebSocket, gRPC, MQTT)
  • CI/CD pipelines without browser dependencies
  • Team-wide mock sharing and collaboration
  • Recording production traffic for test fixtures
  • Load testing with realistic mock responses
  • Sharing mocks via built-in cloud tunnel (no ngrok needed)

Architecture Difference

MSW intercepts requests in the browser. Mockd runs as an independent server.

MSW Architecture

1
App runs in browser
2
Service worker intercepts fetch()
3
Handler returns mock response
Limitation: Browser/Node-only, no multi-protocol support

Mockd Architecture

1
Mockd runs as standalone server
2
App points to Mockd URL
3
Mockd returns configured responses
Advantage: Works with any language, any protocol

Performance Advantage

Mockd is a native Go binary optimized for high throughput.

Native
Go binary performance
vs JavaScript runtime
<30MB
Memory footprint
Minimal resource usage
7
Supported protocols
HTTP, WS, gRPC, GraphQL, MQTT, SSE, SOAP

From the Blog

Ready to Go Beyond Browser Mocking?

Get started with Mockd in under a minute. Single binary, no dependencies, any language.

# Quick install
curl -sSL https://get.mockd.io | sh