Online Random Bitmap Generator

What this tool actually does

Numeric controls default to width 800 px, height 500 px and pixel-block size 10 px. Width and height are constrained to 1..10000 and proportionally reduced when their product exceeds 24 million pixels. Block size is constrained to 1..1000 px.

Checkable behavior

The canvas is filled block by block from the top-left. Each block receives an independently generated CSS HSL color with random hue from 0 up to but not including 360 degrees, fixed saturation 75%, and fixed lightness 55%. Edge blocks are clipped by the canvas when dimensions are not multiples of block size.

Controls, output and limitations

Verified geometry example: width 20, height 10 and block size 5 draws eight blocks in four columns and two rows. The default 800 by 500 canvas with size 10 draws 4000 blocks. A requested 10000 by 10000 canvas is reduced to about 4899 by 4899 to respect the pixel limit.

Randomness uses Math.random with no seed control. Repeating the same settings does not reproduce the same colors, and the output is decorative test art rather than cryptographically random data, a compression-noise simulation, a palette-constrained sprite, or a deterministic fixture.

Set dimensions and block size, press Generate, inspect the pattern, then download PNG. Press Generate again for a new independent pattern. Generation happens in the browser without an upload; large canvases or very small blocks require more work, so use practical dimensions on mobile devices.