Image to Grayscale
Convert an image to grayscale (black and white) and download it as a PNG.
Runs in your browser Your input never leaves your device.
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About this tool
Turn a color picture into grayscale. For each pixel the tool computes a weighted brightness (about 30% red, 59% green, 11% blue, which matches how the eye sees color) and uses it for all three channels. Transparency is left as it was. The image keeps its original size and downloads as a PNG named after your file with -grayscale added, so photo.jpg becomes photo-grayscale.png. It runs in your browser and nothing is uploaded. This is a plain black-and-white conversion with no contrast control; use Image Adjustment if you want to tune brightness or contrast after or before.
How to use it
- Drop an image or choose a file.
- Wait for the grayscale preview.
- Check the size shown.
- Press Download.
Grayscale or pure black and white
Grayscale keeps every shade between black and white, so a photo still shows detail and soft edges. A pure black and white image, also called a 1-bit or threshold image, uses only two colors and looks like a stamp or a scan. This tool makes grayscale. It does not reduce the picture to two colors.
Why the weights matter
The eye is most sensitive to green and least to blue. A plain average of red, green and blue makes bright blue skies and red lips too light or too dark. The tool uses the standard weights 0.299 red, 0.587 green and 0.114 blue, so the gray tones keep the brightness you see in the color photo.
Tips for a better result
- If the picture looks flat, raise contrast in Image Adjustment, then convert here.
- For a partial or faded look, use the Grayscale slider in Image Adjustment instead.
- The output is a lossless PNG. For a photo you want to share, convert it with PNG to JPG to make the file smaller.
- Keep your original. Color cannot be recovered from a grayscale image.
What else changes
The picture is redrawn on a canvas and saved as a new PNG, so metadata from the original, such as EXIF camera details and GPS location, is not carried over. The width and height stay the same.
Common problems
- The picture looks flat
- Straight grayscale can reduce contrast. Raise contrast in Image Adjustment first, then convert.
- File is larger than your JPG
- The output is lossless PNG. Convert to JPG afterward if you need a smaller file.
- Needs a partly colored look
- This tool is all-or-nothing. Use Image Adjustment's Grayscale slider for a partial effect.
Frequently asked questions
Does it work with PNG files that have transparency?
Yes. Only the red, green and blue values are changed. The alpha channel is kept, and the result is saved as PNG so transparency stays.
Can I turn a grayscale image back into color?
No. The color information is replaced by one brightness value per pixel, so it cannot be restored. Keep the original file.
Is my image uploaded?
No. The pixels are converted on a canvas in your browser.