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telnety

VNC guide

Telnety bundles a VNC client that renders RFB streams with noVNC over a local websockify proxy. The result is a native-feeling VNC viewer that works the same way on every platform — no external apps to install, no port-forwarding gymnastics.

How VNC works in Telnety

Telnety spawns a websockify proxy that bridges between the VNC server (RFB 3.7/3.8) and the noVNC renderer embedded in the app. From your perspective there's a single connection to manage; behind the scenes Telnety handles the binary subprotocol and any TLS upgrades.

The path your VNC traffic takes
Telnety UI
  -> noVNC renderer (in-app WebView)
    -> websockify proxy (binary subprotocol)
      -> VNC Server  (typically TCP 5900-5999 or TLS 5901)

Configure a VNC host

New host → VNC protocol. Fields you'll fill in:

  • Hostname — the VNC server address (IP or DNS).
  • Port — default 5900 for display 0; 5901 for display 1; and so on.
  • Auth — pick VNC password, TLS + VNC password, or None for unauthenticated displays. Passwords land in the encrypted vault.
  • Username (optional) — for servers that support VeNCrypt user authentication.
Tunnel VNC through SSH for anything that crosses the public internet. Use the SSH host's Port forwarding tab to expose 127.0.0.1:5900 locally, then connect Telnety's VNC client to localhost:5900. The VNC server itself doesn't need to expose 5900 to the internet.

Quality, scaling, and compression

The Display tab has three knobs that interact:

  • Quality (1-9) — image quality of the JPEG-encoded tiles. Higher is sharper; lower is faster on slow links. The default of 6 is fine over LAN.
  • Compression (1-9) — zlib compression of the framebuffer updates. Higher uses more server CPU but less bandwidth.
  • Encoding preference — Tight is usually best; Telnety falls back through Hextile, ZRLE, and Raw for compatibility with older servers.
  • Scaling — Fit to pane, 1:1, or Custom %. Telnety preserves aspect ratio at all scales.

Clipboard sharing

VNC clipboard sharing flows through the RFB clipboard pseudo-encoding. Telnety enables it in both directions by default for ASCII text. Some VNC servers (notably TigerVNC's default config) limit clipboard size to 1 MiB; large clipboards are silently truncated on those servers, not by Telnety.

View-only mode and read-only sharing

Toggle View only in the connection toolbar to disable input. Useful when you're watching a deploy or pair-programming over a screen-share without wanting to accidentally type.

For workshop-style sharing where you want multiple people watching a single display, most modern VNC servers expose a SecurityType=VeNCrypt view-only mode. Telnety connects to those modes the same way as a full session.

Troubleshooting

  • Black screen on connect — the VNC server is up but isn't sending framebuffer updates. Try moving the mouse on the server, or check the server log for a stuck X session.
  • Authentication fails repeatedly — some VNC servers cap the password at 8 characters and silently truncate. Verify by setting a short password as a test.
  • Keyboard layout looks wrong — VNC sends keysyms, not scancodes. Configure the server-side keymap to match your local layout, or pick the right layout under Display → Keyboard.
  • Connection works on LAN, hangs over WAN — ISPs sometimes throttle port 5900. Tunnel the VNC port through SSH (see the callout above) and connect to localhost.