This 8 by 8 grid generates a number based off of which ones are white and which ones are black. Click on a square to swap it's color. Swap all the squares with the swap button. (First on the right) Change all the squares to black with the X button. (Middle one) Randomize the squares with the random button. (Bottom button) There are also some presets that I made in the top right corner.
Note: The number generated below is not accurate for higher numbers. This scratch project is an idea I had for a game (like Minecraft) with a procedural level generator. The idea is that instead of typing in a number for the seed, you can instead draw a little 8 by 8 picture. There are 18446744073709551616 possibilities.