BuzzKit
Grayscale Image Converter
Convert a color photo to grayscale.
One click converts every pixel to its luminance value.
Uses the standard luminance formula (0.299R + 0.587G + 0.114B) rather than a flat average, which matches how the eye perceives brightness.
How the grayscale image converter works
Every pixel's red, green and blue values are combined into a single luminance value using the standard broadcast formula, then applied back to all three channels.
Convert
One click desaturates every pixel.
Download
Save the black-and-white result.
When a grayscale image is the right choice
Converting to grayscale is useful for black-and-white photography, for printing without color ink, and for checking whether a design has enough contrast without relying on color. The tool combines each pixel's red, green and blue values into a single luminance value, so brighter colors stay brighter and darker colors stay darker.
The conversion changes the pixels, so keep your original if you may want the colors back later. For further adjustments to brightness and contrast, open the result in the Image Filter Editor, and reduce the file size with the Image Compressor.
Frequently asked questions
Is this the same as a saturation slider at zero?
Very close — this uses the luminance formula which tends to look more natural than a flat desaturation.
Can I adjust contrast afterward?
Yes — run the result through the Image Filter Editor for brightness/contrast tweaks.
Does this affect transparency?
No, the alpha channel is left untouched.
Is my image uploaded anywhere?
No. The conversion is done with your browser's canvas, so the image never leaves your device.
Can I get the color back afterward?
Not from the converted file, so keep your original. The conversion replaces each pixel's color with a single gray value.