Image to Grayscale — Desaturate Any Image in Your Browser
Desaturate any image (PNG, JPG, WebP) to 8-bit grayscale. Files never leave your device.
Drop your image here
PNG, JPG, or WebP — up to 50 MB
Converting an image to grayscale — also called desaturation or monochrome conversion — strips the color information while preserving luminance. Unlike a simple average of Red, Green, and Blue channels, this tool uses the BT.709 luma formula (0.2126 × R + 0.7152 × G + 0.0722 × B), which weights green more heavily because the human eye is most sensitive to green light. The result is a perceptually accurate black-and-white image that matches what you’d see if color was removed from your vision.
This tool runs the entire pipeline in your browser. The image is read into an HTML5 Canvas, each pixel is transformed to grayscale, and the result is re-encoded in the same format (PNG stays PNG, JPG stays JPG). No server roundtrip, no upload, no account required. The file never leaves your device. This is especially useful for photographers editing private or client work who don’t want to trust a third-party service with unreleased images.
How to use
Drop your image
Drag a PNG, JPG, or WebP file into the drop zone (up to 50 MB). The image is read locally and never leaves your device.
We desaturate it
Each pixel's color channels are converted to a weighted grayscale using the BT.709 luma formula: 0.2126 R + 0.7152 G + 0.0722 B, producing a natural-looking black-and-white image.
Download the grayscale image
The output file is saved in the same format as the input. Filename gets a `-converted` suffix.
Frequently asked
What is the difference between grayscale and black-and-white?
Grayscale uses 256 levels of gray (8-bit) based on perceptual luminance. Black-and-white (also called threshold or binary) reduces every pixel to either pure black or pure white. This tool produces true grayscale, not binary black-and-white.
Does this use the same formula as Photoshop's 'Desaturate'?
Photoshop's Desaturate command uses a simpler equal-weight average (each channel ÷ 3). This tool uses the BT.709 luma formula (the same as Photoshop's 'Black & White' adjustment), which weights green more heavily to match human perception.
Does the file size change?
Usually within 5%. The desaturated pixels compress about the same as the original. JPEG recompression at 92% quality causes minimal additional loss.
Are my images uploaded?
No. All processing happens in your browser via the HTML5 Canvas API. The file never leaves your device.
Can I convert a batch of images?
In your browser: not yet. For batch processing, we recommend ImageMagick on the command line: `mogrify -colorspace Gray *.png`.
Does this handle transparent PNGs?
Yes. The alpha channel is preserved unchanged. Grayscale is applied only to RGB channels.
Limitations
- No tintingThis tool produces neutral grayscale. It cannot add sepia, cyanotype, or any color cast to the result.
- Single image onlyBatch processing is not supported in v1. Use CLI tools for bulk conversion.
- Lossy recompression for JPGIf your input is JPG, the output is a freshly encoded JPG. Quality is 92% by default, so loss is minimal but not zero.
Platform notes
- macOS
- Works in Safari, Chrome, and Firefox. Preview.app can also desaturate images: Tools → Adjust Color → set Saturation to zero.
- Windows
- Works in Edge, Chrome, Firefox. MS Paint does not offer grayscale conversion, making this tool a convenient alternative.
- Linux
- CLI equivalent: `convert input.png -colorspace Gray output.png` (ImageMagick). For batch: `mogrify -colorspace Gray *.png`.
- Web
- Runs entirely client-side. No upload, no server roundtrip. Open in any modern browser.