UltraVnc Command line Parameters

Here you will find an description of all the command line parameters that could be applied to winvnc.exe , winvncsc.exe (SingleClick) and vncviewer.exe .

WinVNC

Running WinVNC

-service
Runs WinVNC as a service.
-servicehelper
Runs the WinVNC Service Helper app, i.e. the systray icon.
-run
WinVNC is being run as a user-level program.

Installing WinVNC as Windows service

-install
Installs WinVNC as a service.
-sinstall
Installs WinVNC as a service silently, i.e. no message box appears.
-remove
Removes the WinVNC service.
-reinstall
Silently removes WinVNC service, then re-installs it.

Accessing various Configuration Options

-settings
Shows the Properties dialog of an existing instance of WinVNC.
-defaultsettings
Show the Admin Properties dialog of an existing instance of WinVNC.
-multi
WinVNC is being run as a user-level program. Multiple simultaneous instances are allowed.
-fus
WinVNC is being run as a user-level program. Warning about multiple instances is disabled.
-about
Shows the About dialog of an existing instance of WinVNC.
-help

Connecting VNCViewers

-connect host[:display]
Adds a new client to an existing copy of winvnc.
Needs the computer name (DNS name) or IP address and optionally the display number (separated from the host name with a colon (:).
-connect host[::port]
Adds a new client to an existing copy of winvnc.
Needs the computer name (DNS name) or IP address and optionally the port number (separated from the host name with two colons (::).
-autoreconnect
Is used in conjunction with the -connect switch when having a server "back-connect" to a listening viewer. You can use it in a batch file for your clients that are behind a firewall that is not under your control. The batch file looks something like this:
"c:\program files\ultravnc\winvnc" -autoreconnect -connect 12.34.56.78
On the local computer run the viewer in "listening" mode, and have someone on the server end run the batch file. The -autoreconnect will make the server end attempt to reconnect to the listening viewer if the connection drops or is closed. It will immediately reconnect to the listening viewer if the session is closed. Close the listening viewer altogether in order to stop the server end from "autoreconnecting" to your computer. The server attempts to "autoreconnect" for only a few seconds.
Note that this "autoreconnect" param must be before the "connect" one on the command line!
-kill
Kills any already running copy of WinVNC.

WinVNC SingleClick

In addition to the normal WinVNC command line parameters, WinVNC SC supports the following parameters:

-id number
Used with the repeater in mode II. Specifies a number to identify the session. In the -connect parameter use the repeater's name or IP address (and the repeater's port) instead of the remote host name.
-plugin plugin
Use the specified DSM plugin.
-noregistry
Don't store SingleClick DSM settings in the registry. Used in conjunction with the -plugin parameter.
-notrayicon
Do not display the UltraVNC icon in the system tray.
-read only
Don't send keyboard and mouse events to the remote computer.
-username username
Use the specified username.
-password password
Use the specified password.

VNCviewer

VNCViewer supports numerous command line parameters which allow for configuration of nearly every aspect of the viewer.

-help, -? or -h
Print a help message.
-listen [port]
Start the VNCviewer in listen mode. If port is specified, the viewer listens on that port instead of ???.
-restricted
???
-viewonly
Do not send local keyboard or mouse events to the remote computer.
-nostatus
Don't show the status window while connecting.
-nohotkeys
Do not enable hot keys (like CTRL+ALT+F9 for full screen mode etc.). Can be useful in case of conflict with other installed software hotkeys.
-notoolbar
Do not display the toolbar.
-autoscaling
Automatically scale the viewer window so that the remote screen fits at best your local screen size.
-fullscreen
Display viewer in full screen mode.
-noauto
Disable auto mode. Required for using the color options below or saving a custom configuration (otherwise the settings from quick options always override).
-8bit, -256colors, -64colors, -8colors, -8greycolors, -4greycolors, -2greycolors
Set the color depth. Fewer colors can significantly reduce the required bandwidth.
Note: Grey colors only work with 32 bits color screen resolution. 16 or 24 bits color resolutions just don't work with grey colors.
-shared
Share the server with other viewers, i.e. allow several viewers to connect simultaneously to the server.
-swapmouse
Swap left and right button of the mouse.
-nocursor
Do not display any local dot mouse cursor.
-dotcursor
Display the local dot mouse cursor.
-normalcursor
Display the normal local mouse cursor.
-belldeiconify
???
-emulate3
Emulate a 3-button mouse.
-noemulate3
Do not emulate a 3-button mouse.
-nocursorshape
???
-noremotecursor
???
-scale A/B
Scale the display by the factor A/B.
-emulate3timeout Timeout
???
-emulate3fuzz Emul3Fuzz
???
-disableclipboard
Do not transfer clipboard content.
-delay delay
???
-loglevel loglevel
Set the loglevel. This can range from 0 (minimal) to 10 (maximum logging).
-console
Open a console window for log output.
-logfile filename
Log to the file specified by filename.
-config filename
Read the configuration from filename.
-register
???
-encoding encoding
Encoding is either raw, rre, corre, hextile, zlib, zlibhex, tight or ultra. Encodings are described here.
-compresslevel level
Use specified compression level (0..9) for "tight" and "zlib" encodings (Tight encoding specific). Level 1 uses minimum of CPU time and achieves weak compression ratios, while level 9 offers best compression but is slow in terms of CPU time consumption on the server side. Use high levels with very slow network connections, and low levels when working over high-speed LANs. It's not recommended to use compression level 0, reasonable choices start from the level 1.
-quality quality
Use the specified JPEG quality (0..9) for the "tight" encoding (Tight encoding specific). Quality level 0 denotes bad image quality but very impressive compression ratios, while level 9 offers very good image quality at lower compression ratios. Note that the "tight" encoder uses JPEG to encode only those screen areas that look suitable for lossy compression, so quality level 0 does not always mean unacceptable image quality.
-password password
Use the specified password for "classic" VNC authentication.
-serverscale scale
Scale the display on the server side by 1/scale. For instance scale = 2 means that the remote screen dimensions are reduced by 2 ("half screen size"), reducing at the same time the amount of graphical data received by a factor 4 (2^2).
-quickoption option
Select a quickoption. Modem option is default.
  • 1: Auto
  • 2: LAN
  • 3: Medium
  • 4: Modem
  • 5: Slow
  • 7: Ultra
-dsmplugin filename
Use the DSM plugin specified by filename.
-proxy host[:port]
Use the repeater specified by host and optionally port.