About Puzzle Dotter

What it does

Puzzle Dotter has four tools. The dot-to-dot maker traces the main shape in a picture and turns it into numbered dots with an answer key. The paint by numbers generator reduces a photo to a few colours and prints numbered areas with a colour key. The colouring page maker draws clean outlines from a photo, and the grid drawing method printable puts a labelled grid over a picture with a matching blank grid to draw on.

Every page prints on A4 or US Letter, and can be downloaded as a PNG image or an SVG file.

How it works

All the image work happens in your browser. When you choose or paste a picture, your browser reads it and a background worker on your own device does the tracing, colour matching or edge finding, so the page stays responsive. The picture is never uploaded, and nothing is kept once you close the tab. Once a tool page has loaded, it keeps working even if your connection drops.

Each tool page explains the method it uses and links to the published papers behind it, such as Otsu's threshold method, k-means colour clustering and Canny edge detection.

Who makes it

Puzzle Dotter is an independent website. It has no accounts, no adverts and nothing to buy. The site counts page visits with Cloudflare Web Analytics, which uses no cookies; the privacy page has the details.