Developer Setup Installation - Python venv

  • Install Python 3.9

  • Install Git.

  • Using “Build Tools for Visual Studio 2019” installer: - - You require the mandatory selected build tools, and the following optional tools;

    • Windows 10 SDK (or your equivalent Windows Version)

    • C++ CMAKE tools for Windows

    • MSVC v142 (or above) - VS 2019 C++ x64/x86 build tools

    • Default install options are appropriate.

  • Reboot

$ python -m venv C:\ledfx
$ cd C:\ledfx
$ .\Scripts\activate.bat
$ pip install pipwin
$ pipwin refresh
$ pipwin install pywin32
$ python .\Scripts\ -install
$ pip install numpy
$ pip install "chardet<4.0"
$ pip install --upgrade git+
$ git clone -b dev .\ledfx-git
$ cd .\ledfx-git
$ python develop
$ ledfx --open-ui

1. To develop, open up a terminal and activate the ledfx virtual environment

$ C:\ledfx\Scripts\activate.bat

2. Make changes to LedFx’s files in C:/ledfx/ledfx-git. Your changed files will be run when you run LedFx

$ ledfx --open-ui

You can keep the ledfx virtual environment open and keep making changes then running ledfx. No need to reactivate the virtual environment between changes.

Firmware Issues


  • Sending data, WLED going into E1.31 mode but lights not working?

    • Try turning off multicast and setting the start universe to 1.

  • As long as the universe size is set to 510 LedFx should output to all pixels. Maybe something in the code is not working past 1 universe as 1 universe is 170 LEDs

  • Make sure “disable WiFi sleep” is ticked in WiFi Settings on the WLED web interface.

  • How many devices do you have?

    • Try 1 WLED device to start and work your way up to see where the problem lies, whilst monitoring your computer performance usage.

  • Determine if it’s a networking problem: Try pinging the device - any large variances in ping will cause issues - LedFx is extremely latency sensitive. Command prompt ping the IP address of the WLED device. For example: ping


The ESPixelStick firmware is extremely streamlined and by far the lowest latency option.

ESPixelStick will drive all LEDs via the RX pin (like any real pixel pusher FW should do) and will let you have thousands of LEDs in any pixel order you want. The problem with the code is, it can’t handle more than a single universe, which limits you to 170 pixels. More advanced FW will consume input spanning multiple universes.

LedFx Configuration File

Did you try host: or host: your-ipv4 (i.e.: The 127 is your localhost internal network and running anything on that subnet will only be available from that device. Putting it on or your host’s LAN IP opens up the port, 8888 in our case, to other devices on your LAN from your host’s IP.

Speaker Sound

My solution to this exact problem is ChromeCast audios, I have two in a group and ChromeCast to the group. One of them is connected to my DAC that is then connected to my amplifiers, and another is connected to a line in on my computer in a separate room that LedFx is running on.

They’re perfectly synchronized, but if you need to, you can do a delay on any of the ChromeCasts within the group to adjust sync.


Squeezebox Server - Logitech


VBAN audio sync

Using Voicemeeter use VBAN, also allows mobile phone app to play your audio. Needs a little tinkering between multi speaker devices for ms delay. Make sure you have static IP addresses for your device and it does support up to 4 outgoing devices streams.


Networking Improvements

DPC Latency

LedFx is extremely latency sensitive and will expose inherit weaknesses in WiFi. To minimize this, we reccomend:

  1. Disabling WiFi Sleep Mode on WLED.

  2. Minimize WiFi activity on your network - using ethernet where possible.

  3. Ensure router appropriate for number of devices and amount of traffic.

  4. Attempting to ensure your WiFi access point is located in an appropriate area, and is using an appropriate WiFi channel.

Access via LAN

All current builds should be able to be accessed from LAN - please ensure that you allow traffic from port 8888 from the host machine.

Need more help?

Reach out to the LedFx team through Discord. Preferably copy and paste with your answers below

  • New build/recent upgrades?

  • python version?

  • LedFx version you are using?

  • restarted your PC and issue continues?

  • any changes/deleted your LedFx config file?

  • Problem: