Image Grayscale
Convert images to grayscale. Upload or drag-and-drop. Max 12 MB. Processing in your browser only.
Convert images to grayscale. Upload or drag-and-drop an image (max 12 MB). The tool converts it to black-and-white in your browser and lets you download the result. Your image is never uploaded to a server.
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Examples
- Color photo → grayscale → download
- PNG logo → black and white version
FAQ
Why is SVG not supported?
SVG is vector-based. This tool converts raster images (PNG, JPEG, WebP) to grayscale using the canvas.
What is the maximum file size?
12 MB per image.
Is my image sent to a server?
No. Conversion runs in your browser. Your image never leaves your device.
How is grayscale calculated?
A standard luminance formula is used (0.299×R + 0.587×G + 0.114×B) so the result matches human perception. Green contributes most because our eyes are most sensitive to green light.
What is the difference between grayscale and desaturating?
Desaturation averages R, G, B equally: (R+G+B)/3. Grayscale uses a weighted luminance formula that matches how the human eye perceives brightness. The luminance formula produces a more natural-looking result, especially for reds and greens.
Does grayscale reduce file size?
A grayscale PNG can be saved as a single-channel image, which is smaller than full-color. However, the browser canvas outputs 4-channel RGBA by default. File size reduction depends on the output format — JPEG will compress effectively.
Why do black-and-white photos look different from simple grayscale conversion?
Professional black-and-white photography uses channel mixing (boosting or reducing specific color channels before conversion) to control tonal relationships. For example, using a red filter in B&W photography darkens blue skies and lightens reds.
What is grayscale used for in accessibility?
Testing your UI in grayscale reveals whether information is conveyed by color alone (a WCAG 1.4.1 failure). If a button or chart is unreadable in grayscale, color-blind users will struggle. Use patterns, labels, or contrast in addition to color.
How does JPEG handle grayscale images?
JPEG can store true grayscale (YCbCr format with no chroma data), which produces smaller files than full-color JPEG at the same quality. The browser canvas encodes to JPEG in full color by default, even for grayscale content.
Does grayscale conversion lose data?
Yes. Converting to grayscale is irreversible — the color information is permanently lost from the downloaded file. The original source file is unaffected, so always keep a copy.
What formats support single-channel grayscale?
PNG supports 8-bit and 16-bit grayscale channels. JPEG supports grayscale. WebP supports grayscale in both lossy and lossless modes. The browser canvas API outputs images in full RGBA color; true single-channel output requires server-side tools.