Mockbird

Tracking since Apr 30, 2026.

Changelog

• May 17, 2026
  description

  Smart Mock is a lightweight Chrome extension for frontend developers who need to test edge cases — errors, slow networks, conditional responses, real-time streams — without spinning up a backend or modifying production code.
  
  ━━━ WHAT IT DOES ━━━
  • Intercept fetch / XHR / WebSocket / SSE by URL pattern (glob, substring, regex)
  • Swap responses with custom JSON, status codes, latency, headers
  • Capture real requests and turn them into mocks with one click
  • Compare mock vs live API in real time (drift detection) — see exactly what changed
  • GraphQL operation matching, header pattern matching, request body matching
  • Transform mode: write a JS function that modifies the real response
  • Simulate errors (4xx / 5xx), timeouts, network failures
  • Per-mock and global enable/disable — kill switch always one click away
  • Dark mode, keyboard shortcuts, full keyboard navigation
  
  ━━━ WHY IT'S DIFFERENT ━━━
  • No code changes.
  • No desktop app.
  • Lightweight.
  • Affordable. Free forever for the core feature set.
  • 100% local. Your mocks live in chrome.storage.local — nothing leaves your machine.
  
  ━━━ EXPORT / IMPORT ━━━
  • Export your mocks as JSON to share with your team
  • Import HAR files from DevTools to convert real traffic into mocks
  • Export to MSW (Mock Service Worker) format if you want to migrate to in-code mocking later
  
  ━━━ PRIVACY ━━━
  Smart Mock runs 100% on your device. No analytics, no telemetry, no tracking, no remote calls. Your mocks, captured requests, and configuration never leave

  Mockbird is a lightweight Chrome extension for frontend developers who need to test edge cases — errors, slow networks, conditional responses, real-time streams — without spinning up a backend or modifying production code.
  
  ━━━ WHAT IT DOES ━━━
  • Intercept fetch / XHR / WebSocket / SSE by URL pattern (glob, substring, regex)
  • Swap responses with custom JSON, status codes, latency, headers
  • Capture real requests and turn them into mocks with one click
  • Compare mock vs live API in real time (drift detection) — see exactly what changed
  • GraphQL operation matching, header pattern matching, request body matching
  • Transform mode: write a JS function that modifies the real response
  • Simulate errors (4xx / 5xx), timeouts, network failures
  • Per-mock and global enable/disable — kill switch always one click away
  • Dark mode, keyboard shortcuts, full keyboard navigation
  
  ━━━ WHY IT'S DIFFERENT ━━━
  • No code changes.
  • No desktop app.
  • Lightweight.
  • Affordable. Free forever for the core feature set.
  • 100% local. Your mocks live in chrome.storage.local — nothing leaves your machine.
  
  ━━━ EXPORT / IMPORT ━━━
  • Export your mocks as JSON to share with your team
  • Import HAR files from DevTools to convert real traffic into mocks
  • Export to MSW (Mock Service Worker) format if you want to migrate to in-code mocking later
  
  ━━━ PRIVACY ━━━
  Mockbird runs 100% on your device. No analytics, no telemetry, no tracking, no remote calls. Your mocks, captured requests, and configuration never leave

• May 17, 2026
  name

  Smart Mock

  Mockbird

Permissions & access

Permissions

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Host access

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Screenshots