You upload a photo, you get a numbered outline back. The middle step is less magic than it looks, and knowing it helps you pick settings that give an outline you will enjoy painting.

What happens to your photo

The generator shrinks the picture, smooths out sensor grain, then groups similar pixels into the number of colors you chose. Areas too small to hold a brush stroke are merged into their neighbor, and each remaining area gets the number of its color, placed where the area is widest. Colors are numbered from lightest to darkest.

It all runs in your browser. The photo is not sent anywhere, which is also why the result appears in a few seconds, even on a phone. There is no account, no watermark over the outline and no limit on photos.

Choosing the settings

• 12 colors suit a cartoon, a logo or a first try with children.
• 24 colors are the usual choice for a pet or a landscape.
• 36 and 48 colors keep the subtle shades of skin and fur, at the cost of many more small areas.
• Relaxed detail gives large areas that are easy to fill. Fine detail keeps eyes, whiskers and lettering readable, but expect several hundred more areas.

The counter under the preview shows how many areas you would paint. Change a setting and it updates, so compare before you print.

Printing the result

The PDF is US Letter. Page 1 is the numbered outline, page 2 the color key with a hex code and share of the picture for each color, plus a small painted preview. If you plan to use acrylics, print page 1 on card of 200 g/m2 or more, since regular paper wrinkles under wet paint. For markers or pencils, 12 or 24 colors is plenty, as few sets go further.

Paint by number or color by number

Same idea, different medium. A color by number sheet is filled with pencils or markers, a paint by number with a brush. The PDF works for both.

When to order a canvas instead

The printout gives you the outline. It does not give you the paints, the canvas or the size. If you want your photo as a finished piece to hang, a custom paint by numbers kit arrives ready to paint: numbered canvas, acrylics matched to the numbers and brushes. Start from a sharp photo in even daylight with a clear subject, at least 1,500 pixels on the long side after cropping, or 2,500 for the 50x65 cm and 60x60 cm formats. The preview on the product page is an approximation, not a proof sent for approval.

A good test: run your photo through the generator first. If the outline looks like something you would enjoy painting, the kit will too.