PepsTools

Image Tools

Image to Grayscale

Convert an image to grayscale with a before/after preview and quality control for lossy formats.

How to use it

Choose an image and output format. Create file shows the grayscale preview. Download saves the file.

Example

Preview updates after Create file. JPEG and WebP quality is adjustable.

Input

photo.jpg to grayscale PNG

Result

photo-gray.png using Rec. 709 luminance weights

How it works

Each pixel uses 0.2126 R + 0.7152 G + 0.0722 B. Alpha is preserved for PNG and WebP when the encoder keeps it.

Common errors

  • JPEG lost transparency JPEG has no alpha. Use PNG or WebP.
  • The image looks flat That is expected for grayscale. Adjust quality only for JPEG/WebP size.

Limitations

This is not a darkroom tool with channel mixers. Animation is flattened. Size limits match other image tools.

Privacy

The file stays in your browser. PepsTools does not upload it, store it, or send it to another service. Clear the tool or leave the page to drop it from memory.

Questions

Which luminance formula is used?

Rec. 709 coefficients: 0.2126, 0.7152, and 0.0722.