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Convert Image to Grayscale

Turn color photos into black and white. Choose how gray is calculated, add a sepia tone if you like, and compare the grayscale image with the original.

Updated
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Your images

JPG, PNG, WebP, AVIF, GIF, or BMP. Up to 20 images, 50 MB each. Ctrl+V pastes.

    Settings

    Gray from

    The result keeps the original format. JPG files are saved again at quality 92; PNG stays lossless.

    Preview

    Your preview will appear here
    1. Choose or drop images on the left
    2. Pick how gray is made
    3. Compare, then download

    How to use the grayscale converter

    1. Add one or more images.
    2. Keep Luminance (Rec. 709) for natural-looking gray, or pick Average.
    3. Tick Sepia tone for a warm, old-photo look.
    4. Drag the divider on the preview to compare, then download.

    How it works

    Every pixel's red, green, and blue values are replaced by one gray value.

    • Luminance (Rec. 709): gray = 0.2126 R + 0.7152 G + 0.0722 B. The weights follow how bright each color looks to the eye, so green counts most and blue least. This is the standard for sRGB images.
    • Average: gray = (R + G + B) ÷ 3. Simple, but blue skies and red flowers come out lighter than they look.
    • Sepia: each channel becomes a mix of all three, for example R' = 0.393 R + 0.769 G + 0.189 B, which gives a brown tint.

    The alpha channel is not touched, so transparent areas stay transparent. The result keeps the original format.

    Examples

    • Pure red (255, 0, 0) becomes gray 54 with luminance, but 85 with the average.
    • Pure green (0, 255, 0) becomes 182 with luminance: green looks much brighter than red or blue at the same value.
    • Pure blue (0, 0, 255) becomes 18, almost black.
    • White stays 255 and black stays 0 with either method.

    Grayscale or black and white?

    In everyday speech both mean a photo without color. Strictly, a grayscale image has up to 256 shades of gray, while a pure black and white (1-bit) image has only two. This tool makes grayscale images, which is what people usually want for photos. The file still stores three color channels, so it opens in any app without trouble.

    Limitations

    • Color can't be brought back from a grayscale file. Keep the original.
    • JPG files are saved again at quality 92.
    • There are no contrast or brightness controls. For a CSS-only effect on a web page, use the CSS Filter Generator.

    Frequently asked questions

    Which grayscale method should I use?

    Luminance (Rec. 709) for photos, because it matches how bright colors look to people. The average method is there for when you need the simple (R + G + B) ÷ 3 formula.

    Does converting to grayscale make the file smaller?

    A little for PNG and WebP, often not much for JPG, because the file still stores color channels. Run the result through the Image Compressor to shrink it further.

    Is transparency kept?

    Yes. Only the red, green, and blue values change. The alpha channel stays exactly as it was in PNG, WebP, and AVIF files.

    Can I turn a grayscale image back into color?

    No. The color information is gone once the file is saved. Keep your original if you might need color later.

    Often used together with the Image Grayscale.

    • Image Compressor

      Shrinks JPG, PNG, WebP, and AVIF files with a quality slider and a before/after view.

    • CSS Filter GeneratorDeveloper Tools

      Builds CSS filter effects on a sample image and copies the filter CSS.