Photo to thermal
Turn any photo into a crisp black-and-white print for your thermal label printer. Dithering tuned for thermal dots, sized exactly to your label, and everything runs on your device.
Drop your photos here
JPEG, PNG or WebP. Several photos become a multi-page PDF, one label per photo.
Runs entirely in your browser. Your photos are never uploaded.
How it works
- Drop in one or more photos, or pick them from your device.
- Choose the label size, your printer's resolution, the fit and a dithering style.
- Adjust brightness, contrast, dot gain and sharpen until the preview looks right.
- Download the PDF. Each photo becomes one page at the exact label size.
- Print at 100% / Actual Size with the matching paper size selected.
Why dithering
A thermal print head is either on or off: every dot is pure black or nothing at all. Grayscale photos have to become dot patterns, and the driver inside your printer does a crude job of it. This tool does the conversion properly, at your printer's exact resolution, with tone controls that compensate for how thermal dots spread on the paper. The PDF it produces is already 1-bit, so the driver has nothing left to scale or re-dither.
Printer settings
Set the paper size to match the label you picked, print at 100% / Actual Size, and use your printer's highest darkness if the print looks faint. Detailed guides per printer:
- Rollo 4×6 settingsRollo X1038, Rollo Wireless, Rollo USB
- Munbyn 4×6 settingsMunbyn ITPP941, ITPP129, RW401, 941B
- Zebra 4×6 settingsZebra ZD410, ZD420, ZD421, GK420d, GX420d, ZP450
- DYMO 4XL 4×6 settingsDYMO LabelWriter 4XL, 5XL
- Phomemo 4×6 settingsPhomemo PM-241, PM-246, M110, M120
- POLONO 4×6 settingsPOLONO PL60, PL420, P31S
Shipping labels too?
The main tool converts marketplace shipping-label PDFs to 4×6, with the same on-device privacy:
Private by design
Your photos are read, dithered and saved by your own browser. They are never uploaded, and there is no server that could store them.
Frequently asked questions
Why does the preview look like dots instead of a normal photo?
A thermal printer can only make pure black dots, never gray. Dithering turns your photo's grays into dot patterns of different density, which reads as shades of gray once printed. What you see in the preview is exactly what the printer will put on the label.
Which style should I pick?
Atkinson works best for most photos: clean highlights and punchy shadows. Smooth (Floyd–Steinberg) suits portraits and soft gradients. Retro gives a regular crosshatch pattern that prints very evenly. Line art is a hard threshold for logos, QR codes and text, not photos.
My print came out too dark. What do I change?
Raise the dot gain slider first. Thermal dots spread slightly on the paper, which fills in midtones; a higher dot gain value lightens them back. If the whole image is dark, lower brightness a little.
What can I use this for?
Thank-you cards, logo stickers, care instructions, QR code cards and small product photos on 4×6, 4×4, 4×3, 2×1 or 2.25×1.25 inch labels, whatever your thermal printer takes.
Are my photos uploaded anywhere?
No. The conversion runs entirely in your browser. Your photos never leave your device, and closing the tab wipes everything.
Does it work on a phone?
Yes. Pick photos from your camera roll, adjust the sliders, download the PDF, then print it from your label printer's app at 100% scale.