| API | Scope | Chrome | Firefox | Safari | User Gesture Needed | |------------------|---------------------------|--------|---------|--------|----------------------| | Web Serial | Serial ports (USB, BT) | ✅ | ❌ | ❌ | Yes (requestPort) | | WebUSB | USB devices (bulk/ctrl) | ✅ | ❌ | ❌ | Yes | | WebHID | Human interface devices | ✅ | ❌ | ❌ | Yes | | Web Bluetooth | BLE devices | ✅ | ❌ (partial flags) | ❌ | Yes | | WebSocket + native bridge | Any | ✅ | ✅ | ✅ | N/A (native app required) |
Even if navigator.serial exists, you must ensure the call is user-initiated: web serial api browser support
document.getElementById('connectBtn').addEventListener('click', async () => if ('serial' in navigator) try const port = await navigator.serial.requestPort(); // proceed catch (err) console.error('User cancelled or error', err); else showFallbackMessage(); ); const ports = await navigator.serial.getPorts(); if (ports.length === 0) // No previously granted ports – need user gesture again | API | Scope | Chrome | Firefox