Image to Black & White Converter

Convert images to black and white online for free. Choose between Luminance, Average, or Lightness algorithms. Private, client-side processing.

How It Works

  1. Upload your image by clicking the upload button or dragging and dropping the file into the designated area.
  2. Choose your preferred conversion algorithm: Luminance, Average, or Lightness.
  3. Instantly preview the black and white result alongside the original image.
  4. Switch between algorithms to find the look that best suits your image.
  5. Download the converted black and white image to your device with a single click.

Example

Input: Color photo of a sunset at the beach (beach_sunset.jpg, RGB pixel: R=255, G=140, B=50)
Result: Grayscale value using Luminance algorithm: 0.299×255 + 0.587×140 + 0.114×50 = 76.245 + 82.18 + 5.7 ≈ 164

FAQ

Absolutely. All processing happens entirely in your browser on your own device using client-side JavaScript. No images or data are ever sent to any server, so your files remain completely private.

The tool supports JPEG, PNG, WebP, and GIF formats. We recommend PNG for lossless output quality.

Luminance uses a weighted formula (0.299R + 0.587G + 0.114B) based on human color perception and produces the most natural-looking result. Average calculates the simple mean of the R, G, and B values. Lightness takes the average of the lightest and darkest channel values.

Yes, the tool is 100% free with no registration, no hidden fees, and no watermarks added to your images.

Yes. Since processing is done in the browser, performance depends on your device's capabilities. Very large files may take a moment longer to process, but there is no strict file size limit imposed by the tool itself.