This action starts one or both of the HTML5 WebSocket servers, connected to by the Lacewing Blue HTML5 and UWP clients.

It takes two parameters:

    1. Insecure HTML5 Server port, or zero.
      The default insecure HTML5 port is 80, but hosting on this port will be blocked on some platforms, so you may want to host on port 6122 instead.
  1. Secure HTML5 Server port, or zero.
    The default secure HTML5 port is 443, but hosting on this port will be blocked on some platforms, so you may want to host on port 6123 instead.


The difference between these two versions:

  • HTML5 client apps running on a HTTP website can use both Secure or Insecure WebSocket servers.
  • HTML5 client apps running on a HTTPS website can only use Secure WebSocket server.
    To host the secure server, you have to load the SSL/TLS certificate before hosting, using either of the HTML5 Server > Load SSL/TLS certificate actions.
  • UWP clients can use either version.


For more details on getting TLS certificates, or why ports will be blocked on some platforms, read the Guides > Hosting a server > Hosting a WebSocket Server topic.


You cannot host on the same port as a hosting Relay server (usually 6121) or Flash server (always port 843); you will get an error about "port in use" or "access denied".


If you pass port 0 for a WebSocket server that is already hosting, it will stay hosting unaffected. If it was not hosting and you pass port 0, it will not be started by this action.

To stop either or both WebSocket servers, use the HTML5/UWP Servers > Stop hosting WebSocket server(s) action.


Specifying port 0 for both parameters will create an error.

Specifying a negative port, or port above 65535 in either parameter, will produce an error.

Attempting to start secure server without a SSL/TLS certificate loaded will produce an error.

Any errors will result in no change happening, even if only one parameter is invalid.