Grayscale image
Upload a photo and FileTinker desaturates it to grayscale, or switch to black & white for a pure two-tone result with an adjustable threshold. It runs entirely in your browser, so your image is never uploaded.
Related conversions
Need pure two-tone instead? Open the dedicated page:
How to convert an image to grayscale
- Upload your image (JPG, PNG, WebP, HEIC and more).
- Choose Grayscale or Black & White, and adjust the threshold if needed.
- Download your converted image.
About grayscale and black & white
Grayscale removes all colour while keeping the full range of brightness, turning a photo into shades of grey — the classic black-and-white-photograph look. It is useful for a timeless aesthetic, for print, for reducing distraction, or for preparing an image for further processing.
True black & white (also called two-tone) goes further: each pixel is forced to pure black or pure white using a brightness threshold you control, which gives a bold, high-contrast, stencil-like result. Both run entirely in your browser, instantly and privately.
Converting to grey is not a simple average of red, green and blue. Human eyes are far more sensitive to green than to blue, so standard conversions weight the channels — roughly 30% red, 59% green and 11% blue — to keep perceived brightness looking natural. That weighted value is called luminance, and it is why a proper grayscale conversion resembles classic black-and-white film rather than the flat, muddy result a plain average produces.
Grayscale earns its keep beyond aesthetics. Convert a document or chart before printing on a mono laser printer to preview exactly what will come out, or desaturate reference photos so colour stops biasing a drawing or value study. The two-tone mode suits jobs that need pure black and white: cleaning up a scanned signature, turning a whiteboard photo into crisp notes, or preparing artwork for stamps, stencils and engraving.
Frequently asked questions
How do I convert an image to grayscale?
Upload your image and it's converted to grayscale instantly. Switch to Black & White for a pure two-tone version, and drag the threshold slider to control how much becomes black versus white.
What's the difference between grayscale and black & white?
Grayscale keeps the full range of grey tones, like a classic monochrome photo. Black & white is pure two-tone — every pixel becomes either black or white based on a brightness threshold, for a high-contrast, stencil-like look.
Does it reduce the image quality?
No. The image keeps its original resolution; only the colours change. PNG and WebP stay in their format (with transparency); other formats are saved as high-quality JPEG.
Is my image uploaded?
No. The conversion happens entirely in your browser, so your photo never leaves your device.
Why do two different colours look the same after converting to grayscale?
Because grayscale keeps only brightness, and those two colours were equally bright. Hue is discarded, so a saturated red and a saturated green of similar luminance collapse onto nearly the same grey. If important elements vanish into each other — coloured text on a coloured background, lines in a chart — lighten or darken one of them first so they differ in brightness, not just in hue.