Sudoku, with magical shapes

Who makes Shapedoku

Shapedoku is made by SnailPixel, a small independent game studio. We design and build our own games from the ground up: the puzzle generator, the solver, the interface, the backend that powers the leaderboards, and this website. Because we write the code that generates and validates every puzzle, we also understand the logic behind the techniques we describe in our guides.

The game is available as a free web app at app.shapedoku.com and as a mobile app on Google Play. Both run on the same puzzle engine and share the same accounts, progress and leaderboards.

Why shapes

Numbers all share the same footprint, so a busy grid takes real effort to scan. Shapes differ by their whole outline, which the eye recognizes almost instantly. They are also kinder to colorblind players, because every token is distinct by form as well as color. The result is a calmer, more welcoming puzzle that still delivers the exact same logic.

The nine tokens are a triangle, a hexagon, a circle, a crystal, a heart, a diamond, a square, a crescent moon and a lotus. Internally they map to the digits 1 to 9, which is why any classic Sudoku technique, from naked singles to X-Wings, works unchanged in Shapedoku.

What you can do here

• Play classic puzzles across five difficulties, from a Beginner practice tier to Extreme.
• Learn the game with a guided tutorial and hints that explain the reasoning behind each move.
• Take on a fresh Daily Challenge and build a streak.
• Try challenge modes like Speed, No Mistakes and Perfect Run.
• Use notes, hints and smart cleanup to solve harder boards.
• Earn XP, climb levels and compare times on the leaderboards.
• Solve any puzzle with our free solver, or generate and print your own.
• Read hundreds of guides on solving techniques, Sudoku variants and the puzzle habit, organized by topic.

How we write our guides

Every article on this site is written and edited by the Shapedoku team. We work from the same puzzle logic we implement in the game. When a guide describes a technique such as a hidden pair or a finned X-Wing, the pattern has been checked on real grids, usually with our own solver, before it is published. We prefer worked examples over vague advice, we say plainly when a technique does not apply, and we revise articles when we find a clearer way to explain something or when the game changes.

We do not invent statistics, studies or expert quotes. When we write about the benefits of a puzzle habit we stick to what a daily logic practice can reasonably offer and avoid medical claims. The full standards are on our editorial policy page.

How the project is funded

Shapedoku is free to play and free to read. The website and the game are supported by advertising: display ads served by Google on this site, and in-app ads in the mobile game. Advertising never influences what we write, which techniques we recommend, or how puzzles are generated. We do not publish sponsored articles or paid placements. Our privacy policy explains how ads and cookies work and how you can opt out of personalized advertising.

Free, and yours to keep

Shapedoku needs no account. You can start a puzzle in seconds as a guest, and your progress is saved on your device. If you want to sync across devices and join the leaderboards, you can sign in, but you never have to. Guest play works forever.

The philosophy

We think a puzzle should feel calm, look beautiful and respect your time. No forced logins, no walls, no clutter. Just a clear board, a gentle challenge, and that quiet satisfaction of a solved grid. Whether you have five minutes or fifty, Shapedoku is here for it.

Corrections

If you spot an error in a guide, a puzzle that seems to break its own rules, or anything else that looks wrong, please tell us. We correct mistakes promptly and note significant corrections inside the affected article.

Say hello

Questions, ideas or bugs? Email [email protected] or use the contact page. We read every message.