The sudoku guides
Direct, sourced and dated answers, from the team that makes SudoKoum. No content-farm filler.
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And to pick your app: the 2026 comparison
SudoKoum vs Sudoku.com and Brainium. Real prices, ads, social modes, verified and dated.
Sudoku techniques: the 5 levels, from last free cell to Swordfish
Each difficulty tier maps to specific techniques. Here they are, in the order you will need them.
Play togetherHow to play sudoku with friends: the asynchronous challenge guide
Real time or turn-free, how a link-based duel works, and five ideas to get your family or office hooked.
ScienceIs sudoku good for your brain? What the science actually says
A study of 19,000 adults, prefrontal cortex imaging, and the caveats the miracle sellers leave out.
Choose wellSudoku without ads: why it is so rare and how to find one
The three business models of mobile sudoku, and how to spot an app that respects your time.