LED Matrix Editor

Design pixel patterns and animations for 8x8 / 16x16 LED matrices, MAX7219 strips and NeoPixel grids. Multi-frame, undo/redo, drawing tools, transforms, and Arduino / Python / MicroPython / JSON export. Click and drag the grid; everything runs in your browser.

Click a sample, then hit Play.

Frame 1 / 1

0 / 64 lit

Native

FPS4 fps250 ms total · 0.25 s

Frames

Click a thumbnail to switch frames. Drag to reorder. Double-click a thumbnail to set its delay.

Export

// LED matrix: 1 frame, 8 x 8
const uint8_t frame_count = 1;
const uint16_t frame_delays_ms[1] = { 250 };
const uint8_t frames[1][8] PROGMEM = {
  { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }  // frame 0
};

Import

Auto-detects JSON workspace vs raw bytes.

Keyboard shortcuts

Shortcuts work while the mouse is over the editor:

P pencil, E eraser, F fill, L line, R rectangle
I invert, X clear
Arrow keys shift the active frame
Cmd/Ctrl+Z undo, Cmd/Ctrl+Shift+Z (or Cmd/Ctrl+Y) redo

How drawing works

A pencil click toggles a cell. A drag after that paints with the value the first cell got. Line and rectangle draw from where you press to where you let go, and they light cells when the first cell was off (or turn them off when it was on). Fill flips the touching area of cells that share the clicked cell's state.

Byte order

Bytes export uses bit 7 as column 0 (the convention used by LedControl, FastLED and the xantorohara editor). A 16 wide row is two bytes, left half first.