Black and White Image

Color out, gray shades in its place.

FREE - NO SIGN-UP - RUNS ON YOUR DEVICE

Your files stay on your device

  • Colorto gray
  • 1picture per run
  • Alphatransparency kept
  • 0uploads
Specification

Black and White Image at a glance

Input formats
JPG, PNG, WebP, BMP and GIF
Output formats
Same as input
How it converts
Luminance formula, per pixel
What it is not
Gray shades, not two flat tones
Transparency
Transparent areas stay clear
Price
Free
Account required
No
Where it runs
On your device
How to

How to use Black and White Image

  1. 1

    Add a picture

    Open a color picture.

  2. 2

    Look at the result

    Check the gray version.

  3. 3

    Download

    Save the gray version.

Questions

Frequently asked questions

Is this pure black and white, or gray?

Gray. Each pixel becomes the shade that matches its brightness, so the picture keeps its mid-tones. A two-tone threshold conversion is not offered here.

Can I set the contrast or mix the channels?

No. The conversion runs one way, with a fixed luminance formula. Darkroom-style channel mixing needs a photo editor.

Will the file end up smaller?

Sometimes. Dropping the color information can shrink a PNG noticeably, while a JPG may barely move. It depends on the picture and the format.

What happens to a transparent PNG?

Transparency survives. Clear pixels stay clear and only the colored ones are converted, so a logo keeps its cut-out background.

Background

How brightness becomes gray

Every pixel is measured for brightness and redrawn as the gray that matches it, so the picture keeps its full range of tones. It is not a two-tone conversion to pure black and pure white.

  • The eye does not read all colors as equally bright. Green looks brighter than blue at the same intensity, and red sits between them.
  • A luminance formula weighs the red, green and blue in each pixel to work out how bright it looks, then uses that as the gray.
  • Averaging the three channels instead would flatten the picture, turning strong reds and blues into the same dull middle gray.
  • Because the mid-tones are kept, the result is what film photographers mean by black and white: a full range of grays.

Full specification

Specification of the Black and White Image tool
Input formatsJPG, PNG, WebP, BMP and GIF
Output formatsThe same format as the picture you put in.
How it convertsEach decoded pixel is weighed by a luminance formula and redrawn as the gray of matching brightness.
What it is notNot a two-tone threshold. The grays in between are kept, and there is no contrast, brightness or channel control.
TransparencyKept. Clear areas of a PNG stay clear; only colored pixels are changed.
PriceFree
Account requiredNo
Where it runsIn your browser tab. Nothing is sent anywhere.
Next step

Keep going with the same files

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