Websocket 'wss' error while trying to launch openems ui in webbrowser

hello, new to openEMS.
trying to follow the instructions in the ‘getting started’ section to try the features of this opensource project.
have already succeeded steps 1-3 and configured the websocket api controller. in step 4, while trying to open the url in the instruction in chrome (os: ubuntu), the webpage is only partially loaded and no login page is shown as indicated in the instruction.
‘inspector/network’ of chrome showing errors indicate websocket upgrade failure as page attempted to connect to the insecure websocket endpoint ‘ws: url’

would appreciate it if someone can give me a walk-around on this issue, thanks


Hi Steve and welcome to the OpenEMS Community!

In step 4 of the Getting Started guide I do recommend you to follow the link:

If you plan to actively develop on OpenEMS UI, you can now also setup a development environment for it using this guide. Otherwise just go ahead with the hosted version:

As you are running everything locally with default settings, UI should try to establish a “ws”-connection and not “wss” (i.e. non-encrypted websocket).

Also there seems to be an issue currently that sometimes causes a blank page. Refreshing the browser tab should help in that case (see Setup IDE for OpenEMS UI: not working - #5 by NiallDarwin). We are in the process to fix this issue.


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thanks Stefan,
it works and really appreciate your help