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Black and White Image Converter

Make a photo or picture black and white: greyscale with every shade, or pure black and white for documents and signatures. Several at once, nothing uploaded.

Private · on device. Runs in your browser: your file is not uploaded. No sign-up.

JPG, PNG, WebP or iPhone HEIC; several at once
Your pictures are not uploaded. They are changed in this browser tab and saved in their own format (JPG, PNG or WebP; HEIC as JPG), at full size. See-through parts of a PNG stay see-through. With pure black and white, each picture gets its own level, picked from its own pixels.

Black and white: at a glance

What it does
Make a photo or picture black and white: greyscale with every shade, or pure black and white for documents and signatures.
Price
Free, with no limit on use
Sign-up
Not needed
Your files
Processed in your browser and not uploaded to a server
Works on
Android, iPhone, iPad, Windows, Mac and Linux, in any modern browser
Made by
The Daily Toolbox (www.thedailytoolbox.com)

Greyscale or pure black and white

Greyscale

Every colour becomes the grey of its brightness, with all 256 shades in between, which is what people usually mean by a black and white photo. Brightness is weighted the way the eye sees it (green looks lighter than blue), the same weighting television and JPEG use, so the picture keeps its depth instead of looking flat.

Pure black and white

Every pixel becomes either black or white, nothing in between. That is the clean look for scanned documents, signatures, stamps, line drawings and anything you want to print crisply or photocopy. The level that separates dark from light is picked from each picture by default (Otsu’s method, the standard way to split a picture into dark and light); turn that off to set it yourself, lower for a lighter result, higher for bolder lines.

What else to know

  • Each picture is saved in its own format at full size: a JPG stays a JPG, a PNG stays a PNG with its transparency, an iPhone HEIC becomes JPG.
  • The colour cannot be brought back from the black and white copy; keep your original.
  • For a signature on a form, the signature tool also cleans the paper to white and sizes the file for the portal.

Frequently asked questions

What is the difference between greyscale and black and white?

Greyscale keeps every shade of grey, like a black and white photograph. Pure black and white has only two colours, black and white, like a photocopy, which suits text and signatures.

Is my picture uploaded?

No. The pictures are read and saved again by your own browser, inside this page, and are never sent to a server. You can turn off Wi-Fi once the page has loaded and it still works.

Does it make the file smaller?

A little at most, because the file keeps its format and size in pixels. To make it smaller, compress it afterwards.

Can I do many pictures at once?

Yes. All of them get the same style, each with its own automatic level, and come as one ZIP.

Is a transparent background kept?

Yes, for PNG and WebP. Only the colours change.

Is the Black and white free?

Yes. The Black and white on The Daily Toolbox is free to use as often as you like, with no watermark and no file limit beyond what your device can handle.

Do I need to sign up or install anything?

No. It works in your web browser on a phone or computer, with no account and nothing to install. You can add the site to your home screen to open it like an app.