Is my image uploaded to a server?

No. All processing is done with the HTML5 Canvas API entirely in your browser. Your image never leaves your device and nothing is stored on any server.

What is the Luminosity method?

Luminosity uses the ITU-R BT.601 weighted formula: gray = 0.299 × R + 0.587 × G + 0.114 × B. It weights green most heavily because the human eye is most sensitive to green light. This produces the most perceptually natural grayscale result.

What is the Average method?

Average computes gray = (R + G + B) / 3, treating all three channels equally. It is the simplest approach and often produces a slightly flat or washed-out look compared to luminosity.

What is the Desaturation method?

Desaturation converts each pixel from RGB to HSL color space, sets the saturation to zero, then converts back to RGB. The result equals (max(R,G,B) + min(R,G,B)) / 2 and tends to produce lighter midtones than the luminosity method.

Which output format should I choose?

Choose PNG for lossless quality and transparency support. JPG is smaller but lossy and drops the alpha channel. WebP offers a good balance of quality and file size in modern browsers.

What image types are supported?

The tool accepts JPG, PNG, WebP, and any format your browser can decode via an element. HEIC and AVIF support depends on your browser version.

Image Grayscale Converter

Name: Image Grayscale Converter
Availability: InStock
Author: Nham Vu

Upload a color image, pick a grayscale method, and download the black-and-white result — all inside your browser.

Image Grayscale Converter

Click or drag image here

JPG, PNG, WebP

Grayscale Method

Luminosity Perceptually accurate — weighted R×0.299, G×0.587, B×0.114 Average Simple equal mix — (R + G + B) / 3 Desaturation HSL saturation set to zero — (max + min) / 2

Output Format

Before / After Preview

Upload an image to see the before and after preview

Done!

Summary

Upload a color image, pick a grayscale method, and download the black-and-white result — all inside your browser.

How it works

Click the upload area or drag and drop a JPG, PNG, or WebP image.
Select a grayscale method: Luminosity, Average, or Desaturation.
Click "Convert to Grayscale" to process the image.
Compare the original color image and the grayscale result side by side.
Choose an output format (PNG, JPG, or WebP) and click "Download".

Use cases

Create black-and-white versions of photos for editorial or artistic projects.
Prepare grayscale product images for print-ready layouts.
Strip color from UI screenshots before using them in documentation.
Compare different grayscale rendering methods for photo editing workflows.
Generate monochrome thumbnails or social media assets quickly.
Remove color information before applying further image processing.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu