How can you play multi-grid (overlapping) sudoku on iPhone and Android?
Very few apps ship multi-grid sudoku at all, and only a handful are worth your time: Conceptis MultiSudoku (curated hand-made puzzle packs), samurai-sudoku.com in the browser, print collections — and Sudoku by Joseph, which generates unlimited puzzles across eight overlapping layouts, more than any other single app we know of. This page explains what multi-grid sudoku actually is, maps the whole variant family, and compares every realistic option honestly, including the ones we don't make.
What is multi-grid (overlapping) sudoku?
A multi-grid — or overlapping, or gattai ("merged" in Japanese) — sudoku prints two or more complete 9×9 grids so that they share one or more 3×3 boxes. Every grid must be solved by normal sudoku rules, and here's the hook: a digit placed in a shared box has to be legal in every grid that box belongs to. The shared boxes become information channels — a deduction in one grid ripples into its neighbor, which unblocks a third, which loops back to the first.
That's why multi-grid solving feels different from just doing five sudokus in a row. Individual grids in a well-made gattai puzzle are usually not solvable on their own; you're forced to rotate between fronts, carrying constraints across the overlaps. It rewards patience and organization more than exotic technique — which is exactly why people who find classic sudoku too quick fall in love with it.
The full multi-grid family
The family runs from two grids to five. "Gattai-N" is the generic name for N overlapping grids; several layouts also carry traditional names.
| Variant | Grids | Layout | Where to play it |
|---|---|---|---|
| Twodoku (Gattai-2) | 2 | Two overlapping grids — the entry point | Sudoku by Joseph; Conceptis MultiSudoku; print |
| Tripledoku | 3 | Three interlocking grids in a chain | Sudoku by Joseph; Conceptis MultiSudoku; print |
| Gattai-3 | 3 | Three grids sharing regions | Sudoku by Joseph; Conceptis MultiSudoku; print |
| Kazaguruma (Windmill) | 5 | Five grids in a rotationally symmetric pinwheel | Sudoku by Joseph; occasional print collections |
| Sohei | 4 | Four grids in a cross, hole in the middle | Sudoku by Joseph; rare in print |
| Samurai (Gattai-5) | 5 | Center grid overlapping four corner grids | Sudoku by Joseph; Conceptis MultiSudoku; samurai-sudoku.com; many books |
| Cross | 5 | Five grids in a cross-shaped arrangement | Sudoku by Joseph; occasional print collections |
| Flower | 5 | Five grids in a tight flower layout | Sudoku by Joseph; rare in print |
Rules and solving notes for the rare four in that table — Windmill, Sohei, Flower and Gattai-3 — are covered in depth in the rare multi-grid family guide; Samurai has its own full guide. For where each variant sits in the wider sudoku landscape, see every sudoku variant explained.
Your real options, honestly compared
The App Store and Google Play are wall-to-wall classic sudoku; searching "samurai sudoku" surfaces a lot of junk. These are the options that actually deliver, including the competition.
Conceptis MultiSudoku (iOS & Android)
Conceptis is one of the most respected puzzle publishers in the world — they supply newspapers globally — and MultiSudoku is a polished, reliable app covering overlapping layouts including Samurai-style and Twodoku-style puzzles. Every puzzle is hand-made and curated, and it shows in the quality. The model is pay-per-pack: the app comes with starter puzzles, then you buy additional volumes of a couple dozen puzzles each. If you solve a puzzle a day, you'll be buying packs regularly; if you want a finite set of excellent puzzles, this model serves you well. That's the honest structural difference versus a generator: curation versus unlimited supply.
samurai-sudoku.com (web)
samurai-sudoku.com is a free website with Samurai puzzles playable directly in the browser. Perfectly decent for desktop solving; the trade-offs are the usual web ones — it needs a connection, the mobile experience is cramped for an 800-cell puzzle, and there are no native app conveniences like proper pencil-mark ergonomics or state that survives interruptions gracefully.
Print books
Samurai sudoku books are plentiful and cheap, and there's a real argument for paper: a five-grid puzzle is physically large, and a big printed page beats any phone screen for overview. Downsides: pencil-mark erasing at scale gets miserable, mistakes are expensive, and the rare layouts (Sohei, Flower, Kazaguruma) barely exist in print at all.
Sudoku by Joseph (iOS & Android)
Our app, so calibrate accordingly — but the factual differences are checkable. It ships eight multi-grid layouts (Twodoku, Tripledoku, Gattai-3, Kazaguruma, Sohei, Samurai, Cross, Flower) plus 16×16 — including Sohei, Flower and Kazaguruma, which virtually no other app offers at all. Puzzles are generated on-device, so the supply is unlimited at every difficulty from Easy to Diabolic, and everything works offline. There are no lives, no coins and no energy meters in any mode — relevant in a format where a single puzzle can take an hour. The multi-grid variants are premium (which also removes the ads from the free tier), with a 7-day trial; pricing varies by country, so check the App Store. The free download includes Classic, Jigsaw and Killer if you want to evaluate the solving interface before trying multi-grid.
Bottom line
Want a curated shelf of hand-crafted Samurai puzzles and don't mind buying volumes? Conceptis MultiSudoku is genuinely good. Want to solve on a desktop for free? samurai-sudoku.com. Want the whole family — including the layouts nobody else ships — in unlimited supply on your phone, with no mid-puzzle monetization? That's the case for Sudoku by Joseph.
Getting started with multi-grid sudoku in Sudoku by Joseph
- Install the app and start the trial
Download Sudoku by Joseph for iPhone, iPad or Android. The multi-grid variants are premium; the 7-day trial unlocks all of them, so you can find out whether the format suits you before paying anything.
- Begin with Twodoku on Easy
Two overlapping grids teach the core skill — treating the shared box as a constraint in both grids — without the scale. Solve a few until crossing the overlap feels natural.
- Step up to Gattai-3
Three grids sharing regions introduces the real multi-grid rhythm: rotating between fronts when one grid stalls and carrying deductions across the overlaps.
- Take on Samurai
Five overlapping grids, with the center as the crossroads. Work the corner grids first and treat the center as the puzzle's clearing house. From there, Sohei, Flower and Kazaguruma are sideways steps into rarer geometry, not harder ones.
Other options worth knowing
Beyond the apps above: if you specifically want hand-set puzzles with artistic intent, the puzzle-setting community around competitions and solving channels regularly publishes overlapping specials for free. And if your interest is really "a bigger single puzzle" rather than overlapping grids, 16×16 sudoku scratches a similar endurance itch with simpler geometry — several dedicated 16×16 apps exist alongside ours.
Frequently asked questions
Do the overlapping boxes count for both grids?
Yes — that is the entire mechanic. A digit in a shared 3×3 box must satisfy the row, column and box constraints of every grid the box belongs to. Rows and columns never cross between grids; only the shared boxes connect them.
Is Samurai sudoku harder than classic sudoku?
Longer, not necessarily harder cell-for-cell. The techniques are the same ones you use on a single grid; the added skills are organizational — knowing when to switch grids and using the overlaps as bridges. A Diabolic classic puzzle can demand harder pure logic than an Easy Samurai.
Can I play multi-grid sudoku offline?
In Sudoku by Joseph, yes — puzzles are generated on the device, so airplane mode works fine. Conceptis puzzle packs also work offline once downloaded. Web options like samurai-sudoku.com need a connection.
Which app has the most multi-grid variants?
To our knowledge, Sudoku by Joseph, with eight overlapping layouts — we know of no other single app that ships Sohei, Flower and Kazaguruma at all. Conceptis MultiSudoku covers the more common overlapping layouts with excellent hand-made puzzles sold in packs. If we've missed an app, we'd genuinely like to hear about it.
Eight overlapping layouts, unlimited puzzles
12 variants, a Daily Challenge with streaks — and never any lives, coins or energy bars. The download is free.
