Grayscale Converter

Summary: How to Convert an Image to Grayscale Free and Privately

Converting an image to grayscale replaces each pixel's color with one shade of gray between black (0) and white (255). Add your images, choose one of seven methods (Luminosity is the default), set the Intensity (100% is full grayscale), compare with the Before/After slider and download each image, or all of them as a ZIP. The result is a standard RGB file in which red, green and blue are equal, saved at full size.

It runs in your browser; nothing is uploaded (you can check the Network tab in DevTools). JPG, PNG and WebP files are saved in the same format; other formats such as GIF, BMP or AVIF are saved as PNG. Transparency is left as it is.

Fine-tune a result with the contrast adjuster or the brightness adjuster. For a warm vintage tone instead, try the sepia filter.

Table of Use: Which Setting for Which Result

The methods differ most on saturated colors. Luminosity uses Gray = 0.21 R + 0.72 G + 0.07 B, BT.709 uses 0.2126, 0.7152 and 0.0722, BT.601 uses 0.299, 0.587 and 0.114, Average uses (R + G + B) ÷ 3 and Lightness uses (max + min) ÷ 2. Linear Luminance applies the BT.709 weights to linear light and converts back to sRGB.

Features

• Seven methods. Luminosity, Average, Lightness, Linear Luminance, BT.709, BT.601 / NTSC and Custom Weights, whose red, green and blue sliders are scaled to add up to 100%.
• Intensity from 0 to 100%. At 0% the image is unchanged; at 100% every pixel is pure gray.
• Partial Grayscale. Drag a rectangle on the preview or type Left, Top, Width and Height, then convert inside it or keep it in color.
• Before/After Comparison. A divider with grayscale on the left and the original on the right, usable with the keyboard.
• Batch with one ZIP. Each image keeps its own settings until you copy them to all. Files are named photo_grayscale.jpg, and duplicate names are numbered.
• Fast previews, full-size saves. Previews use a copy up to 1,200 pixels on the long side; downloads are processed at the original size and can be sent on to the image compressor or the PNG to JPG converter.

How to Use the Grayscale Converter

1. Click Select Images, or drop files on the upload area. Several at once is fine.
2. Under Conversion Algorithm, pick a method. For Custom Weights, move the Red, Green and Blue sliders.
3. Set Intensity. Leave it at 100% for full grayscale.
4. Optional: in Partial Grayscale, click Select Area, drag on the preview, and choose "Grayscale inside the area" or "Keep the area in color". Press Esc or Done Selecting when finished.
5. Drag the divider in Before/After Comparison to judge the result.
6. Click Download Grayscale Image, or Download All (ZIP) when you have several.

To read the exact gray of a pixel, use the image color picker. For a moody finish, add a vignette; to flip tones, use the color inversion tool.

Who Can Use It

• Photographers and artists making black-and-white prints, or tuning color with the saturation adjuster first.
• Designers and teams who need visual consistency across pictures from different sources.
• Anyone printing documents or handouts on a black-and-white printer, or checking that a design still reads without color.

FAQs