noVNC (HTML5 VNC client) without the sugar
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Diet noVNC: noVNC (HTML5 VNC Client) without the sugar


Diet noVNC is a simplified version of noVNC. Diet noVNC is also licensed under the LGPLv3.

Diet noVNC is just an experiment in shrinking noVNC down to the bare minimum for a usable HTML5 VNC client.

noVNC is 120 KB of Javascript + HTML.

Diet noVNC is 22 KB of Javascript + HTML (less than 10 KB w/ Packer 3).


That is a good question. Essentially, I was inspired by the Javascript 10K Apart contest to do something neat using less than 10K of Javascript + HTML. Unfortunately, the contest was already done by the time I started.

Also, I enjoy applying minimalism to code (sometimes called "code golf"). There is a deep hacker satisfaction from taking something large and stripping it down to the bare essential. In some ways it is similar to creating a Quine; both require a conceptual leap in understanding of a given language.


Diet noVNC is not intended to replace noVNC in any sense. The amount of data sent via the VNC protocol in just a few seconds can be orders of magnitude larger than the size of the full noVNC client so the code size is really a non-issue in practice.

Diet noVNC is not an example of good coding practices. While it passes JSLint, I make liberal use of techniques that have minimal code size, but that I would not use in regular code.


  • All code modules have been combined into vnc.js and are no longer usable as standalone libraries.
  • The API is more rigid, easy integration is not a core goal.
  • There is less debug and stastics reporting.
  • The data send and framebuffer request algorithms have been simplified and may not work as well with high latency connections.


  • wsproxy (WebSockets to TCP proxy script)
  • WebSockets emulation (must have native WebSockets)
  • VNC Password Authentication
  • RRE protocol
  • Tight PNG protocol
  • Colour Map (non-true-color) support
  • Local Cursor rendering
  • Clipboard support
  • 'info' and 'warn' logging levels
  • sendKey API

Still there

  • Raw, CopyRect Hextile, and DesktopSize encodings
  • Encryption (wss://) support via 'encrypt=1' query parameter.
  • Some debug output (console) via 'debug=1' query parameter.
  • Send CtlAltDel button
  • Good performance (almost as good as noVNC).


See the noVNC README for full usage instructions. You will probably need to run wsproxy from noVNC in order to use Diet noVNC.

Diet noVNC does not support password authentication (another reason not to use it for anyting except experimentation). If you use vncserver to start your VNC server, you may need to make a copy of the script and comment out the authType seting near the beginning of the script.

Default connect parameters can be provided in the query string: