Image to Grayscale
Free Local ProcessingFree online image grayscale tool. Convert color images to black-and-white grayscale using the international standard luminance weighting, with batch support for JPG, PNG, and WebP. Suitable for document scanning, artistic effects, and print preflight checks. Files are never uploaded; everything is processed in your browser.
Drag files here, or
Up to 20, max each 50.0 MB
How to Use
- 1 Click "Select File" or drag images (JPG / PNG / WebP) to the upload area
- 2 You can select multiple images at once
- 3 Click the "Convert to Grayscale" button
- 4 A single image downloads directly; multiple images are downloaded as a package
FAQ
Q: Which grayscale algorithm is used?
The ITU-R BT.601 luminance formula: gray = 0.299×R + 0.587×G + 0.114×B, matching the standard used by mainstream image software.
Q: Which formats are supported?
JPG, PNG, and WebP. PNG keeps its alpha channel, and JPG output quality does not degrade.
Q: Is my image uploaded to a server?
Never. All pixel-level processing happens locally in your browser.
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