Skip to main content

Shikaku #43

0/7
00:00
Shikaku Puzzles

September 14, 2026

Progress saves automatically

Daily

Shikaku Puzzles

Play Shikaku puzzles free online. A new daily Shikaku every day, a permanent archive, and 600+ rectangle puzzles from 5x5 to 20x20. No signup, works on mobile.

PlayHow to play

How to Play Shikaku

  1. 1.

    Divide the grid into rectangles and squares along the gridlines.

  2. 2.

    Every rectangle must contain exactly one number.

  3. 3.

    That number equals the rectangle's area — a 6 sits in a rectangle covering exactly 6 cells (1×6, 2×3, 3×2, or 6×1).

  4. 4.

    Rectangles fill the whole board with no gaps and no overlaps.

  5. 5.

    Every puzzle has exactly one solution, so you never need to guess — draw by dragging from one corner of a rectangle to the opposite corner.

About Shikaku Puzzles

Shikaku is a Japanese logic puzzle published by Nikoli since 1989 under the name 四角に切れ (Shikaku ni kire — "divide by squares"). You may also know it as Rectangles, Divide by Box, or Sikaku. The rules fit in one sentence: divide the grid into rectangles so that every rectangle contains exactly one number, and that number equals the rectangle's area. A 6 lives in a rectangle of six cells — 1×6, 6×1, 2×3, or 3×2 — and when every cell on the board belongs to exactly one rectangle, the puzzle is solved.

What makes Shikaku special among grid puzzles is how geometric the logic feels. There is no arithmetic to carry and nothing to memorize; instead you reason about space. A prime number can only be a thin strip. A clue crowded against a wall has nowhere to grow but inward. Two large clues competing for the same corridor can each claim only what the other must leave behind. Good boards resolve like a chain of small proofs, and finishing one leaves the grid tiled in clean, colorful blocks.

Every puzzle on this site is generated and then machine-verified to have exactly one solution, then graded by a solver that mimics human technique: easy boards fall to singles and forced rectangles, while medium and hard boards demand common-cell deductions and orphan-prevention thinking. You never have to guess — if you're stuck, a forced move is always waiting somewhere.

Play the shared daily Shikaku to build a streak, browse the permanent archive of past dailies, or work through more than 600 free puzzles across five board sizes, from one-minute 5×5 warm-ups to hour-long 20×20 giants. No account, no downloads — it works in any browser, on phones as well as desktops, and your progress saves automatically.

Features

  • A new Shikaku every day

    One shared daily board on a gentle weekday-to-weekend difficulty curve — plus a permanent archive of every past daily.

  • Five board sizes

    From quick 5×5 warm-ups to giant 20×20 marathons, with easy, medium, and hard tiers at every size.

  • Every puzzle verified unique

    Each board is machine-checked to have exactly one solution — you never have to guess.

  • Autosave & shareable links

    Progress saves in your browser automatically, and every board has a permanent URL you can send to anyone.

Shikaku FAQ

Shikaku is a Japanese logic puzzle first published by Nikoli in 1989. You divide a grid into rectangles so that each rectangle contains exactly one number, and that number equals the rectangle's area in cells. The rectangles must tile the whole grid with no gaps or overlaps. It's also known as Rectangles, Divide by Box, or Sikaku.

Drag from one corner of a rectangle to the opposite corner to draw it around a number. The number tells you the exact area the rectangle must cover — a 4 needs four cells, as a 1×4 strip or a 2×2 square. Start with forced clues like 1s and prime numbers near an edge, then let each placed rectangle narrow down its neighbors.

Yes — everything on this site is free with no account and no downloads. That includes the daily Shikaku, the full archive of past dailies, and more than 600 puzzles across five board sizes from 5×5 to 20×20. Your progress and streak are saved automatically in your browser.

No. Every puzzle here is machine-verified to have exactly one solution, and our grader confirms each board can be finished by pure deduction. If you're stuck, there is always a forced move on the board — usually a number with only one rectangle that fits, or an empty cell only one rectangle can still reach.

A new daily Shikaku is published every day at midnight US Eastern time, and everyone in the world gets the same board. Miss a day and it isn't lost — every past daily stays playable forever at its own permanent URL in the archive.

Start on 5×5 or 7×7 if you're new — they teach the clue-reading habits everything else builds on, and most solve in a few minutes. The classic Shikaku experience is 10×10. When that feels comfortable, the 15×15 and 20×20 giants offer long, layered solves that can span multiple sittings (your progress autosaves).

Yes — the board is built for touch. Drag your finger from corner to corner to draw a rectangle, or tap one corner and then the opposite corner. Long-press a rectangle to remove it, or simply draw over it to replace it. It works in any modern browser on phones, tablets, and desktops.