Private, Offline-First API Testing Client
Test private microservices, webhooks, and local APIs without cloud telemetry. Your API tokens, headers, and payloads stay strictly on your machine.
Why Offline-First Matters for Developers
🔐 Zero Cloud Sync Risk
Never accidentally leak staging API keys or customer PII payloads to a third-party cloud database. Everything is stored locally in IndexedDB.
✈️ Works on Planes & Trains
Develop anywhere without an internet connection. Build collections, craft mock contracts, and run visual test assertions offline.
🚀 Sub-Second Boot Time
Launches in under 50ms compared to bloated 600MB Electron desktop clients that take 10+ seconds to load.
💻 Installable Desktop PWA
Install directly from your browser as a native standalone window on Windows, macOS, and Linux with full offline caching.
Frequently Asked Questions
How does APIFlow execute API calls offline?
APIFlow Studio uses high-performance client-side Service Workers and IndexedDB. Mock responses, contract simulations, and schema validations happen directly on your CPU with 0 network latency.
Does APIFlow require any external server?
No. When mocking, everything is client-side. When testing external live APIs with CORS restrictions, APIFlow includes an optional local proxy relay that forwards requests without storing payloads.
Keep Your API Work Private & Fast
No sign up or account required. Free and open source.
⚡ Open APIFlow Studio