Dot to dot generator

How to make a dot-to-dot

1. Pick a way in: open a photo or a drawing, type a name or word, or choose Tap your own dots and place every dot yourself, with or without a picture underneath.
2. Pick a size: Few dots, big numbers (20 dots, 6 mm numbers), Medium (50, 4 mm) or Many dots, small numbers (150, 2.5 mm), then fine-tune the count anywhere from 10 to 300.
3. Tidy the outline: crop to the subject, raise Simplify to smooth a ragged edge, or tap Fix dots by hand to drag, delete or add dots.
4. Press Reveal to watch the line join from 1 to the last dot, so you see what the child will see.
5. Print: the PDF (A4 or Letter, portrait or landscape) with an optional title, a Name line and the answer page, or a PNG of either page, or print straight from here.

How the dots are placed

The outline. A photo or drawing goes through the same steps as the outline style of Photo to Sketch: grey, a difference of two blurs that marks the dark side of every edge, specks removed, then thinned to one-pixel centre lines. Each centre line is walked into a path; a path whose ends meet is a closed shape. A typed name is drawn in the font and thinned the same way, so you get the middle of each pen stroke. The longest paths get the dots (Outlines with dots), the rest are dropped or, if you tick it, printed as plain lines.

The rule. Corners that turn by 50° or more are kept first, sharpest first, and never closer together than half the even spacing; the remaining dots are spaced evenly along the path between them. A square with 8 dots gets its four corners plus one dot in the middle of each side; a circle with 40 dots gets one every 9°. With several outlines the dots are shared by length, at least 4 for a closed shape and 3 for an open line, and the numbers carry on from one to the next. A closed shape starts at its top (or the corner nearest it) and runs clockwise; a ring marks every start, and the last dot of a closed shape is joined back to its ring.

The numbers. Each number sits beside its dot, on the side away from the shape when there is room, and its box keeps a clear gap of a third of the number height (never under 0.8 mm) from every dot and every other number: 2 mm for 6 mm numbers, 1.33 mm for 4 mm, 0.83 mm for 2.5 mm. If some number cannot be placed that way, all numbers shrink in steps (down to 1.8 mm) and the page tells you; fewer dots or a larger sheet brings them back.

What it cannot do

• It finds edges, not objects. A busy photo (a pet on grass, a face against a bookshelf) gives a messy outline. Crop it, raise Simplify, or tap your own dots over the picture.
• One picture per sheet, and at most 300 dots.
• No colouring-in inside the shape. For a colouring page of a photo use Photo to Sketch; for numbered colours, Paint by Numbers.
• Letters follow one font. Names are drawn in Patrick Hand, which has Latin letters only; anything else (Greek, Cyrillic, emoji) falls back to your device's own sans-serif font, so it looks different on another phone.
• Very crowded pages shrink the numbers. 300 dots round a small shape cannot all carry 6 mm numbers; the page says when it had to make them smaller.
• Nothing is saved. Reloading the page starts again; download the PDF to keep a puzzle.

Questions

How do I make a dot to dot from a photo?

Open the photo. The page finds its strongest outline (the same edge and centre-line steps as the photo-to-sketch tool), keeps the sharpest corners as dots, spaces the rest evenly and numbers them. Crop to the subject, raise Simplify to smooth a ragged edge, or tap Fix dots by hand to move, add or delete dots. A plain background works best: a dark dog on a light wall gives a clean outline, a dog on grass does not.

Can I make a connect the dots puzzle of a name?

Yes. Choose Name or word and type up to 30 letters. The letters are drawn in Patrick Hand, an open-licence print face, and each stroke becomes a run of numbered dots. The count carries on from one letter to the next, and a ring marks where each new line starts, so the child lifts the pencil there.

How many dots should a dot to dot have?

It depends on the picture and on who is joining them, so the page sizes by what you see, not by age. Few dots, big numbers gives 20 dots with 6 mm numbers; Medium gives 50 with 4 mm; Many dots, small numbers gives 150 with 2.5 mm. Any count from 10 to 300 works with any number height; if the numbers cannot all sit clear of each other the page shrinks them and says so.

Does it make an answer key?

Tick Answer page and the PDF gets a second page with the finished line drawn from the first dot to the last, every closed shape joined back to its start. You can also download it as its own PNG. On screen, Reveal draws the line from 1 to the last number in about two seconds.

Is it free, and is my photo uploaded?

It is free with no sign-up, no watermark and no limit on how many puzzles you make. The photo is read and traced by this page inside your browser; it is never sent anywhere, and the PDF and PNG are made on your device too.