Proper black & white, not just desaturated
This tool uses the luminance formula (0.299R + 0.587G + 0.114B) that matches how the human eye perceives brightness — so reds, greens and blues convert to realistic gray tones instead of a flat, muddy result. The intensity slider lets you blend between full color and full grayscale for a partial-desaturation effect.
Everything runs on the canvas in your browser; your photo is never uploaded.