Grayscale Image
Convert an image to black and white. Runs entirely in your browser.
Click to upload or drag and drop
Select an image file
How the conversion works
The image is drawn onto a canvas at its full original size with the browser's 100% grayscale filter, then saved, so the result has exactly the same width and height as the original. Nothing is resampled or cropped; only the color is removed.
Output
PNG images stay PNG and keep their transparency; every other type is saved as a JPEG at 92% quality. The download is always named grayscale.png or grayscale.jpg, so rename it if you're converting several images. Files over 50 MB are rejected.
Getting a stronger black-and-white look
A straight grayscale conversion keeps the original tones, which can look flat. For more punch, convert first and then raise the contrast with Brightness & Contrast. The filter relies on your browser's canvas filter support, so use a current Chrome, Edge or Firefox if the download comes out in color.
A worked example
A 4000 × 3000 JPEG photo comes back as a 4000 × 3000 JPEG named grayscale.jpg, because the dimensions never change. A 512 × 512 PNG logo with a transparent background comes back as a 512 × 512 PNG named grayscale.png, still transparent where it was transparent. The file is re-encoded either way, so a JPEG's size in kilobytes will not match the original exactly.
Size limits you may hit
Besides the 50 MB file limit, the pixel dimensions are checked before anything is drawn. A side longer than 16,384 pixels, or more than 268,435,456 pixels in total (16,384 × 16,384), is refused with a message that quotes the image's size. A 20,000 × 1,000 panorama is rejected on its width alone, even though it only holds 20 million pixels.
What the interface does and does not offer
Conversion starts the moment you choose a file, so there is no button to press and no strength slider: the filter is always at 100%. One image is handled at a time, and choosing another file replaces the previous result.
Frequently asked questions
Can I undo the grayscale conversion afterward?
No — once converted, the original color information is gone from the downloaded file. Keep your original image if you might need the color version later.
Can I make the image only partly gray?
No. The filter is fixed at 100%, so every color is removed. For a muted look rather than pure gray, you would need an editor with a saturation control.
Why was my WebP or GIF saved as a JPEG?
Any image type your browser can open is accepted, but only PNG keeps its format. Everything else is written as a JPEG at 92% quality, which is why the download is named grayscale.jpg.
What is the largest image it can convert?
Up to 50 MB as a file, with no side over 16,384 pixels and no more than 268,435,456 pixels in total. Larger images are refused with an explanation instead of producing a blank file.