Black and White Photo Converter

How it works

People search a black and white photo converter when they need a file they can print, post, or archive — not a CSS filter: grayscale preview that disappears when they save. This page stays in the tab.

1. Drop photos — JPG, PNG, WebP, or GIF. Up to eight files, 15MB each. Nothing is uploaded.
2. Pick a real conversion — Grayscale writes Rec. 709 luma (or Rec. 601 for video stills) into every pixel. Pure black and white uses one threshold so each pixel is 0 or 255. Dithered 1-bit runs Floyd–Steinberg so midtones become a printable speckle instead of a hard posterized edge.
3. Read the numbers — unique gray levels should be 2 after a 1-bit mode. The black-pixel percent tells you if the cutoff is too hungry. A long edge over 4096px is scaled so the tab does not freeze.
4. Download — PNG for the selected file, or a ZIP of the batch. Copy a one-line report if you need to log the settings.

This is not a color-splash editor and not a marketplace compressor. The product is a black and white photo converter that you can prove with the level count.

FAQ

Is this just a grayscale CSS filter?

No. Pixels are rewritten with a luma formula. Saving the PNG keeps the converted values. A CSS filter only paints the preview.

What is the difference between grayscale and pure black and white?

Grayscale keeps up to 256 gray levels. Pure black and white is a single cutoff — a true 1-bit look for stamps, scans, and high-contrast prints. Dither keeps the 1-bit limit but spreads the error so faces do not flatten into blobs.

Do you upload my photos?

No. Decode, luma, threshold or dither, PNG encode, and ZIP all run in the browser. Close the tab and the bytes are gone.

Why did a 5000px photo shrink?

Edges over 4096px are scaled so getImageData stays usable. The report marks those files as scaled.

Can I convert a color GIF?

Still GIFs and the first composited frame of an animated GIF decode like any other bitmap. This black and white photo converter exports PNG, not an animated GIF.