For a festival build (Funky Float @ Mystic Creatures 2025), we needed a proper WLED LED map so 2D animations line up with a strip that snakes around weird shapes. Side-to-side sweeps and API/ArtNet effects only look right when the map matches reality.
All LED-map tools I found online only allow to add LEDs click by click. With several dozen meters of strip that’s not fun. Another feature I we needed was to be able to remove single LEDs or rescale after measuring.
So I wrote a small generator that adds these features, available here as GitHub Gist.
What it does
- Drag-to-paint: hold the mouse down and sweep—every hovered cell becomes an LED in order.
- Rescale later: change the map resolution without losing the drawn path.
- Invert path: flip the LED order if you soldered from the “wrong” side - also allows to flip the entire mapping vertically and horizontally.
- Insert LEDs: add individual LEDs in between existing ones to fix gaps after the fact - or delete LEDs such that the others close up.
- Export JSON: paste the result into WLED’s 2D LED map (LED Preferences).
Future Additions
The next time I need this, I might add the following features:
- Rescale by target LED count per segment (auto distributes points).
- Image-assist: upload a photo, let it auto-trace the strip as a first pass.
If you try it and hit edge cases, open an issue on the gist or send me a note!