Convert colour images to natural-looking black and white.
Our eyes see green as much brighter than blue, even at the same strength. Simply averaging the red, green and blue values ignores that, so greens come out too dark and blue skies too pale. This tool uses the standard broadcast weighting (about 30% red, 59% green and 11% blue), so the black-and-white image keeps the brightness you see in the colour one.
Transparent areas in PNG and WebP images stay transparent.
Grayscale suits scanned documents and forms you want to print cheaply, catalogue photos that need a uniform look, and portraits where colour distracts from the face. It also shows you on screen how a picture will come out on a black-and-white printer or an e-reader, so there are no surprises.
Converting doesn't make a file much smaller by itself, because a JPG still stores three colour channels even when they are equal. If size matters, run the result through the Image Resizer & Compressor afterwards.
In everyday use, yes. Grayscale keeps all the shades of grey between black and white rather than only the two.
Not here. This tool does a single, natural grayscale conversion.
No, the colour information is removed. Keep your original.
No. The conversion happens in your browser.
OneClickly is a set of 119 free tools for PDFs, images, text, everyday math and code. They run in your browser, so the files and text you work with stay on your device.