PixelResize

Convert Image to Grayscale Online Free

Convert a colour photo into elegant black-and-white grayscale. The tool uses perceptual luminance weighting, so bright and dark areas keep their natural balance instead of looking flat — perfect for a classic monochrome look or a neutral background image.

Your files never leave your device. All processing happens locally in your browser.

Drag & drop your image here

or click to browse

Files never leave your device

Up to 50MB per file

Why use this tool

True-to-Eye Tones

Colours are mixed using Rec. 601 luma weights, matching how the human eye perceives brightness, so skin and skies convert naturally.

One Click

Just drop your image in — the grayscale version appears instantly, ready to download with nothing to configure.

100% Private

Files are processed entirely in your browser using the Canvas and WebAssembly APIs. Nothing is ever uploaded to a server.

Free Forever

No account, no watermark, no daily limits. Every tool on PixelResize is free to use as often as you like.

How to grayscale image

  1. 1

    Upload a JPG, PNG or WebP image.

  2. 2

    The tool converts it to grayscale automatically.

  3. 3

    Compare the black-and-white preview.

  4. 4

    Download your grayscale image.

Frequently asked questions

Related tools & sizes

How to Convert an Image to Grayscale the Right Way

Not all grayscale is equal. A naive colour average produces flat, muddy results — proper luminance weighting keeps a photo's natural depth. Here's the difference.