About Shikaku
A quiet place to play one rectangle-dividing puzzle a day, with as much extra practice as you like.
What it is
Shikaku Online is a browser version of the logic puzzle where you split a grid into rectangles guided by numbers. It runs on your phone or computer with nothing to install.
How the puzzles are made
Every puzzle comes from a generator built into this site. It cuts a blank grid into rectangles, places one number in each, and uses a solver to confirm the numbers lead to exactly one solution.
The Daily is created from the calendar date, so a given date always gives the same 10x10 puzzle. A new one arrives at midnight on your device. Practice puzzles are created at random whenever you ask for one.
Free, with no account
The game is free to play and there is nothing to sign up for.
Where your results live
Saved boards, streaks and best times are stored in your own browser on your own device. Clearing that browser's site data erases them, and they do not carry over to other devices. The privacy page has the details.
Credits
The puzzles are generated by the site's own code, so there is no outside puzzle library or data source to credit.
Shikaku Online is a Cain Brands site.