Pure Black and White Converter — No Gray, 1-Bit

How to convert an image to pure black and white

1. Drop your image into the box above, click to browse, or paste it with Ctrl+V.
2. Pick a mode — Threshold for a hard cut-off, Dither for photos, Pixel Art for blocky retro looks — then drag the threshold slider until the balance of black and white looks right. Presets for document scans, logos and engraving set everything in one click.
3. Press Download Image to save a full-resolution PNG — no watermark, no signup.

Threshold vs grayscale: what "no gray" really means

A grayscale image keeps every pixel's full brightness information and only strips the color — you still get 256 shades from near-black to near-white, which is why photos look natural. A threshold conversion is stricter: every pixel must pick a side of the line you set with the slider, so the output contains exactly two colors, #000000 and #FFFFFF. That is what "1-bit" means: one bit of information per pixel. It is the look of old Macintosh graphics, newspaper print and laser engraving files.

Which one do you need? For photographs that should still feel photographic, stay with the natural black and white photo converter. For logos, signatures, documents, stencils, laser cutting, vinyl cutting or any workflow that demands flat color with no in-between shades, the threshold converter on this page is the right tool.

Dithering: the 1-bit trick for photos

A hard threshold on a photo usually looks harsh — soft skin and skies collapse into blobby shapes. Dithering fixes that with an old print-industry trick: instead of deciding each pixel in isolation, the Floyd–Steinberg algorithm pushes each pixel's rounding error onto its neighbors, scattering black and white dots so finely that your eye blends them back into convincing shades of gray. The result is still a true two-color image — any printer, cutter or engraver will read it as pure black and white — but photos keep far more of their detail. Try the Dither mode with a threshold around the middle for portraits, and slide toward black or white to set the overall mood.

Clean signatures and line art to transparent PNG

Sign a piece of paper, photograph it, and turn on Transparent BG: every white pixel becomes transparent while your ink stays solid black, giving you a clean signature stamp you can place on contracts and PDFs. The same workflow cleans up hand-drawn logos, clipart and line art for print. Working from a scan of a document? The Document Scan preset raises the threshold so paper texture and gray noise drop away while text stays crisp. And if the scan came out too dark or accidentally flipped to white-on-black, rescue it first with the PDF page color inverter, then come back here for the threshold cleanup. There is also a Swap B&W switch for the days you need white-on-black output — engraving plates and dark-mode assets often do.

Private, instant, works everywhere

Everything runs locally in your browser with JavaScript — your images are never uploaded to a server, so the tool even keeps working offline once the page has loaded. Open it on an iPhone, an Android phone, a tablet or a desktop; the download is always a full-resolution PNG with GPS and other metadata stripped.

More free image tools

Negato's black-and-white family runs from natural grayscale to 1-bit threshold, with color and geometry tools alongside. Invert image colors to create a photo negative, make a film-style negative, or edit PNG colors to replace and recolor specific shades. Looking for natural shades instead of hard black and white? The grayscale converter and the black and white photo converter keep the full tonal range — all tools are free and watermark-free.

Frequently asked questions