- Home
- 20×20 Shikaku
20×20 Shikaku puzzles
The 20×20 Shikaku has 400 cells and dozens of numbers. Our 20×20 puzzles default to Hard, where some rectangles can only be pinned down by combining several deductions.
0 rectangles · Drag to draw · Tap a rectangle to erase · Ctrl+Z undo · H hint
Solving a 20×20 Shikaku
- Mark the obvious ones everywhere before going deep anywhere.
- Large numbers in open areas are the slowest — leave them until their neighbours are fixed.
- If you get stuck, Check reveals mistakes without spoiling the answer.
New to the puzzle? Read how to play Shikaku and then the strategy guide.
20×20 Shikaku questions
How long does a 20×20 Shikaku take?
Most players finish a 20×20 Shikaku in about 25–50 minutes, depending on the difficulty level and experience. Your personal best and average times are saved in your browser.
How many numbers are in a 20×20 Shikaku?
It depends on the level. Easy puzzles use more, smaller rectangles; Hard puzzles use fewer, larger ones. Whatever the count, the numbers always add up to 400, the total number of cells.
Is every 20×20 puzzle solvable without guessing?
Yes. Every puzzle has exactly one solution, verified by our solver. Easy puzzles need only basic deductions; Hard puzzles may need longer chains of reasoning, but never a lucky guess.