Daily Shikaku Puzzle
One free logic puzzle a day — the same grid for everyone, everywhere.
Ready when you are
Drag to draw · click a box to erase · right-click to remove
What is Shikaku?
Shikaku (四角に切れ, "divide into squares") is a Japanese logic puzzle created by Yoshinao Anpuku in 1989 and published by Nikoli, the studio behind Sudoku. You split the grid into rectangles so that each rectangle contains exactly one number and that number equals its area. It's also known as Divide by Squares, Divide by Box, Rectangles or Cell Blocks — pure deduction, never guesswork.
How to play in 30 seconds
Difficulty levels
Every Shikaku board follows the same rules — what changes with size is how many deductions you must hold at once. Pick the grid that fits the time you have.
| Size | Level | What changes | Typical solve |
|---|---|---|---|
| 5×5 | Starter | Single-step deductions; most rectangles are forced from the first clue you inspect. Learn the rules here. | 1–3 min |
| 10×10 | Classic | Two- and three-step chains appear; prime-number clues (5, 7, 11) become the key anchors. | 5–10 min |
| 15×15 | Hard | Long elimination chains; you must count regions against remaining rows and columns, not just extend clues. | 10–25 min |
| 20×20 | Expert | Full-board bookkeeping; several areas stay ambiguous until distant sections resolve. Pencil-mark territory. | 25–60 min |
The daily puzzle is always 5×5 — the same grid for everyone worldwide. Practice sizes are unlimited.
Streaks, times and the leaderboard
A streak grows by one each day you solve the daily puzzle, and it only counts the daily — one solve per day, no matter how many times you play. Your streak, best time and solved count all live in your browser.
Missing a day resets the streak to zero. There is no catch-up: the count restarts from your next solve, because the streak measures consecutive days, not total days played.
The leaderboard ranks solvers of today's daily by finish time, fastest first — the same 5×5 grid for everyone worldwide, so the times are directly comparable. Practice solves never count toward the streak or the leaderboard.
Refreshing mid-solve keeps your placed rectangles, since the board is saved in your browser as you go. The timer restarts on reload, so your recorded time reflects the session in which you finish.
The puzzle behind LinkedIn Patches
If you've been playing LinkedIn's Patches, you already know Shikaku — Patches is built on exactly the same rules. This daily plays the same way, free and with no account. New to it? Start with the how-to-play guide.
Patches keeps Shikaku's core rule — one clue per region, area equals the number — and adds shape badges (wide, tall, square) plus some un-numbered clues. If you can solve the puzzles here, you can solve Patches; the daily grid on this page is the classic version, with no account and no streak lock-out.
Frequently asked questions
Is Shikaku free?
Yes — every daily puzzle and all practice sizes are completely free, with no account and no ads in your way.
Is Shikaku the same as LinkedIn Patches?
Effectively yes — Patches is built on the same core rule, dividing a grid into rectangles where each holds one clue equal to its area.
What is Shikaku also called?
Shikaku is also known as Divide by Squares, Divide by Box, Rectangles and Cell Blocks.
Do I need an account?
No account is needed — your streak, best time and progress are stored only in your browser.
When does the daily puzzle reset?
The daily puzzle resets at midnight UTC, when the same new 5×5 grid unlocks for everyone worldwide.
Does every puzzle have only one solution?
Yes — every well-formed Shikaku has exactly one solution reachable by logic; if you get a puzzle from elsewhere, the solver will confirm whether it is valid.
Can I play on mobile?
Yes — just drag on the touchscreen to draw rectangles; the board scales to your screen.
What grid sizes are available?
The daily is always 5×5, and practice comes in 5×5, 10×10, 15×15 and 20×20.