VNC

VNC lets you view and control a remote desktop from Zync. The remote computer must already have a running VNC server and a desktop session. Zync provides the viewer; it does not install or start that server.

There are two ways to connect:

Route	Use it when
Saved VNC connection	You want an independent desktop tab that connects directly to a host and port.
VNC Viewer in an SSH workspace	You want to reach a VNC server listening on that SSH host’s loopback address.

Direct VNC needs a trusted network

Direct VNC can expose screen contents and input to the network. Use it only on a trusted network or VPN. Saving a password in Vault protects that stored password; it does not encrypt the VNC transport. The SSH-backed viewer carries the desktop connection through SSH.

Save a VNC connection

1. Open New Connection and choose VNC connection.
2. Enter a Profile name, Host or IP address, and Port. Use the server’s VNC TCP port, not its display number. The default port is 5900.
3. Choose VNC authentication, Remote resolution, and Viewer scale as described below.
4. Choose Save profile to store the settings, or Save & Connect to save and connect if the viewer is idle. Back returns to the connection-type chooser.

Saved profiles appear under VNC PROFILES in the Connections sidebar. That section appears after you create a profile and starts collapsed. Open a profile to show its own tab, then choose Open VNC when ready. A tab opened with Save & Connect starts the connection after saving.

Passwords and Vault

The profile’s VNC authentication control offers:

• Ask for password: enter the server’s password when the viewer requests it.
• Saved Vault credential: select an existing Password entry.
• Save password to Vault: enter a password and Name in Vault to create an encrypted entry when you save the profile.

An SSH host and VNC profile can explicitly link the same Password entry. The profile stores a reference, not the password itself. If you change the saved address or port, select the Vault credential again to confirm its use for that endpoint. Unlocking Vault during an explicit connection attempt lets that attempt continue; cancelling unlock stops it.

Start with a server configured for classic VNC password authentication. Other server authentication modes may require different server settings. If a saved password is rejected, review the credential or choose Try password manually for an explicit retry. See Vault for password rotation and recovery.

Connect through SSH

1. Connect to the saved SSH host in Zync.
2. Open the workspace’s + menu and choose VNC Viewer.
3. Enter the Remote loopback port used by the VNC server on that host, then choose Open VNC.
4. Enter the VNC password if requested.

The target is the SSH host’s 127.0.0.1 address. A server bound only to a different interface will need a matching server configuration. The SSH-backed viewer does not require a separately saved direct VNC profile. It asks for the VNC password when needed.

Disconnecting SSH also closes its VNC connection. This route is separate from Public URLs and does not create a public desktop link.

Resolution and scale

For a saved VNC profile, right-click its tab and choose Display settings… to edit the saved display controls.

Remote resolution controls the size requested from the server:

• Keep server resolution keeps the desktop’s existing resolution. This is the default for saved profiles.
• Auto (match pane) requests a desktop size that follows the available pane.
• A preset or Custom resolution requests a specific width and height when connecting.

The server must support the requested resize. If it cannot apply the size, Zync fits the current desktop to the pane and shows a notice. Custom requests must stay within the limits shown in the form.

Viewer scale changes the local image independently of the remote resolution. Fit to pane is the default and keeps the image proportional. The fixed choices are 50%, 75%, 100%, 125%, 150% and 200%.

The SSH-backed viewer starts with automatic resizing. While connected, the tab’s right-click menu provides Auto-resize and Disconnect. Auto-resize changes the remote resize behavior for the current viewer; saved profile display choices remain available through Display settings….

Reopen and disconnect

Saved VNC profiles and their restored tabs stay on this device. Restarting Zync restores a saved tab without opening the network connection automatically. Select Open VNC to reconnect. A previous desktop image is not restored as a live session.

Choose Disconnect from the connected tab’s right-click menu to return to the connection screen. Closing the viewer releases its connection. Zync pauses desktop updates while the viewer is hidden and refreshes it when you return.

Troubleshooting

• Connection refused: start the VNC server and check its listening address and TCP port.
• Connection timeout: check routing, VPN and firewall rules for the route you selected.
• Password rejected: check the linked Password entry and the server’s authentication mode, or try the password manually.
• Desktop does not resize: use Keep server resolution and Fit to pane, or enable a server configuration that supports remote resizing.
• A desktop error appears inside the viewer: check the remote desktop session and VNC server logs. Connecting successfully does not start or repair GNOME or another desktop environment.

Related docs

• Connections for SSH setup and the connection chooser.
• Vault for shared Password entries.
• Security for desktop and device access boundaries.