Web Remote - UNITRONIX/BetterDesk GitHub Wiki

Web Remote Desktop

BetterDesk includes a browser-based remote desktop client accessible from the web console.

Overview

The web remote client connects to RustDesk peers directly from the browser, with no client installation needed. It supports:

Feature HTTPS HTTP
Video codec VP9, H.264, AV1, VP8 (WebCodecs) H.264 only (JMuxer fallback)
Max FPS 60 fps 30 fps
Audio ✅ Opus ✅ Opus
Keyboard ✅ Full (incl. modifiers, F-keys) ✅ Full
Mouse ✅ Click, right-click, scroll, drag ✅ Click, right-click, scroll, drag
Clipboard ✅ Bidirectional ✅ Bidirectional
Session recording ✅ WebM VP9+Opus ✅ WebM VP9+Opus
Monitor switching ✅ ✅
Quality presets ✅ 4 presets ✅ 4 presets

Note: HTTPS is strongly recommended. WebCodecs API (VP9/AV1) is only available on secure origins. HTTP falls back to JMuxer (H.264 only) with lower performance.

Connecting

From the Devices Page

  1. Click the kebab menu (⋮) on a device row
  2. Select Connect
  3. Enter the device password
  4. The remote desktop opens in a new tab

Direct URL

http://your-server:5000/remote?id=DEVICE_ID

Controls

Toolbar

The remote desktop toolbar appears at the top:

Button Function
Quality Switch between Speed / Balanced / Quality / Best presets
Monitor Select which monitor to view (shows resolution)
Record Start/stop session recording (downloads WebM on stop)
Fullscreen Toggle fullscreen mode
Disconnect End the remote session

Keyboard Shortcuts

All standard keyboard shortcuts pass through to the remote machine, including:

  • Modifier keys (Ctrl, Alt, Shift, Win/Meta)
  • Function keys (F1-F12)
  • Special keys (PrintScreen, Scroll Lock, Pause)
  • Ctrl+Alt+Delete (when supported by the remote OS)

Mouse Input

Action Encoding
Left click TYPE_DOWN | (BUTTON_LEFT << 3)
Right click TYPE_DOWN | (BUTTON_RIGHT << 3)
Middle click TYPE_DOWN | (BUTTON_MIDDLE << 3)
Scroll TYPE_WHEEL | (direction << 3)
Move Position sent as coordinates relative to canvas

Quality Presets

Preset Image Quality FPS Use Case
Speed Low 30 Slow connections, basic tasks
Balanced Balanced 30 General use
Quality Best 30 Detail work, design, reading
Best Best 60 High-bandwidth, professional use

Quality changes take effect immediately via Misc message to the peer.

Session Recording

Record sessions as WebM video (VP9 + Opus audio):

  1. Click Record in the toolbar (circle icon turns red)
  2. Perform your remote desktop tasks
  3. Click Record again to stop
  4. The recording downloads automatically as a .webm file

Recordings capture the canvas at 15 fps. Audio is included if active during the session.

Monitor Switching

For multi-monitor setups:

  1. Click the Monitor dropdown in the toolbar
  2. Select the desired display
  3. The view switches to the selected monitor
  4. Primary indicator shows which monitor is the default

Each monitor shows its resolution (e.g., Monitor 1 (1920×1080) ★).

Video Pipeline

HTTPS (WebCodecs)

Peer → H.264/VP9/AV1 frames → WebSocket → WebCodecs VideoDecoder → Canvas
  • Negotiates codec via VideoDecoder.isConfigSupported()
  • Supports VP9 (preferred), H.264, AV1, VP8
  • Hardware acceleration when available
  • video_received ACK sent before decode for optimal pipeline

HTTP (JMuxer Fallback)

Peer → H.264 frames → WebSocket → JMuxer → MSE → Video element → Canvas
  • JMuxer converts raw H.264 NALUs to MP4 fragments
  • MSE SourceBuffer trimmed at 2 seconds to prevent overflow
  • Auto-seek when buffer latency exceeds 500ms
  • Health check every 1000ms with stall recovery

Stall Recovery

If no frames arrive for 5 seconds, the client automatically requests a refreshVideo keyframe from the peer to resume the stream.

Technical Details

Connection Flow

  1. Client opens WebSocket to Node.js console (/ws/remote/{id})
  2. Console proxies through Go server relay
  3. NaCl key exchange establishes encrypted channel
  4. Login message sent with password, codec preferences, FPS
  5. Peer responds with video/audio streams

Browser Requirements

Browser WebCodecs JMuxer Status
Chrome 94+ ✅ ✅ Full support
Edge 94+ ✅ ✅ Full support
Firefox 130+ ✅ ✅ Full support
Safari 16.4+ Partial ✅ H.264 only

Known Limitations

  • JMuxer (HTTP) is limited to H.264 at ~30 fps
  • FileTransfer is not supported in web remote (use RustDesk desktop client)
  • Audio quality depends on network bandwidth
  • Some keyboard shortcuts may be intercepted by the browser (e.g., Ctrl+W)