Free Browser Tool · Runs Locally · No Upload

Thermal Image Dithering Preview

Upload any photo and see exactly how it would look printed on thermal paper — using the same dithering algorithms (Floyd-Steinberg, Jarvis-Judice-Ninke, Sierra, and more) built into Thermal Image Printer and Bluetooth-USB Thermal Printer+.

Quick answer: Thermal printers can only print pure black or pure white dots — no grey. Dithering is the algorithm that converts a photo's grey and colour tones into a black-and-white dot pattern that looks like it has shades of grey from a normal viewing distance. This tool runs the exact same algorithms as our Android apps, entirely in your browser — nothing is uploaded anywhere.

Click to choose a photo, or drag one here
JPG, PNG, or WebP — processed entirely on your device
Original
Thermal Print Preview

Which Method Should You Use?

8 Dithering Methods, Explained

Floyd-Steinberg

Error-diffusion — spreads each pixel's rounding error to its neighbours. The gold standard for photos, faces, and product shots.

Jarvis-Judice-Ninke

Spreads error across a wider 5×3 neighbourhood for softer gradients and cleaner flat areas. Best for logos and text.

Sierra

A refined error-diffusion filter that reduces the "worm" artefacts sometimes seen in Floyd-Steinberg. Good for detailed textures.

Two-Row Sierra

A lighter version of Sierra using fewer neighbouring pixels — a fast, balanced default.

Ordered Dither 4×4 / 2×2

Uses a fixed threshold pattern instead of error diffusion — faster, with a regular grid-like texture. Good for quick previews.

Threshold

No dithering at all — every pixel is either pure black or pure white. Best for high-contrast line art and simple icons.

Print This for Real — Not Just Preview It

These are the exact same algorithms running inside our Android apps. Connect a Bluetooth or USB thermal printer and print the real thing.