Weighted luminance
Uses R 0.299, G 0.587, and B 0.114 to better match human brightness perception.
Grayscale Image Converter
Convert color images to grayscale. Adjust brightness and contrast. Processed entirely in your browser.
Image Studio
Optimize, convert, and grayscale images in one place.
Your image stays in this browser and is not uploaded to a server.
Grayscale conversion turns color information into luminance
Black-and-white images remove hue so shape, contrast, and light become easier to judge. This tool reads the uploaded image on a canvas and converts each pixel with weighted RGB luminance before saving the result as a PNG.
Conversion rules
Browser-side canvas
Pixels are processed in your browser canvas rather than by a server upload pipeline.
PNG output
The download saves the current canvas result as a PNG file.
How to use
- Upload an image.
- Review the grayscale result shown in the canvas.
- Download the converted PNG if the preview looks right.
Frequently asked questions
Why not use a simple average?
Weighted luminance reflects that human vision is more sensitive to green than to red or blue.
Is my original file changed?
No. The tool creates a new canvas result and does not modify the source file.
Does transparency remain?
The RGB channels are converted to gray while the alpha channel is kept.
Image results can vary with browser rendering and the color space of the original file.