Convert to GRAYSCALE, Free
Files convert instantly in your browser. 100% private, any file size, no account needed.
Drop your GRAYSCALE file here
or click to browse. Any file size.
Conversion runs entirely in your browser. Your file never leaves your device.
How to convert to GRAYSCALE
Converting an image to grayscale removes color information, leaving only luminance values that express the image in shades of gray from pure black to pure white. Grayscale images are used in print cost reduction, artistic effect, document scanning, machine learning preprocessing, medical imaging display, and accessibility contexts where color should not be relied on to convey information.
The conversion runs in your browser via WebAssembly. Your image never leaves your device. The grayscale algorithm weights the color channels according to human luminosity perception (typically: 0.299 R + 0.587 G + 0.114 B), producing a perceptually natural desaturation rather than a simple average.
Upload your image
Drop any raster image (JPG, PNG, WEBP, BMP) into the converter. The WebAssembly engine reads the pixel data locally.
Choose the grayscale method
Select from luminosity weighting (perceptually accurate), simple averaging, or desaturation (HSL lightness). Luminosity weighting is the most natural-looking for photographs.
Preview
Review the grayscale preview before downloading to confirm the result meets your expectations.
Download
Click Download to save the grayscale image in your chosen format (PNG for lossless, JPG for smaller file size).
Frequently asked questions
What is the difference between grayscale and black-and-white?
Grayscale has a continuous range of gray tones from black to white. Pure black-and-white (bitmap) has only two values: each pixel is either black or white. Grayscale is what photographers and designers usually mean when they say 'black-and-white photography'.
Why does luminosity weighting look more natural than averaging?
Human vision is most sensitive to green light and least sensitive to blue. Luminosity weighting (0.299R + 0.587G + 0.114B) reflects these sensitivities. A simple average treats all channels equally, making reds look too dark and blues too bright.
Is my image uploaded to a server?
No. Processing runs locally in your browser via WebAssembly.
Will the output have a smaller file size?
If saved as a true grayscale PNG (1 channel instead of 3), the file is smaller. If saved as an RGB image with equal R, G, B values, the compression benefit is less. Choose true grayscale output for maximum size reduction.
Can I convert RAW or HEIC photos to grayscale?
If the converter accepts RAW/HEIC input formats via its WebAssembly decoder, yes. Otherwise, convert to JPG or PNG first, then apply the grayscale conversion.