About this site
One rule shaped everything here: if the site claims a number is correct, it has to be able to show you why.
The problem with most sudoku help
Search for how an X-Wing works and you get a diagram: four tidy cells, arrows, and a sentence about rectangles. Then you go back to your puzzle and cannot find one, because real boards are not tidy. They are half-filled, the pencil marks are messy, and the digit you need has five possible homes, not two.
There is a second problem, closer to the game itself. Most hint buttons give you a number. You learn nothing, and you are one step further from being able to finish the next puzzle alone.
What this site does instead
The hint in the game never just hands over a digit. It works out the next step the way a person would, then shows the chain: which cells were compared, what got ruled out, and which technique the step belongs to. Every step in that chain can be opened to see the reasoning behind it.
The articles follow the same rule. Each one starts from a board pulled out of an actual game — not a drawing — and the positions in the text can be checked against the candidates in the figure. If the article says the digit has exactly two homes in a column, you can count them in the picture.
How the puzzles are made
Boards are generated, not taken from a book. A full grid is produced, then clues are removed one at a time while a solver confirms the solution stays unique. Difficulty is not guessed from the number of empty cells; it is set by the hardest technique the puzzle actually requires, measured by replaying it the way a human solver would.
The nine tutorial levels are built the same way, with one extra constraint: each level stops at the exact position where the technique it teaches is the next thing you would need. That position is found by replaying the puzzle, not by choosing a nice-looking board after the fact.
What it does not do
- No account, no sync. Scores live in your browser. Switch devices and they do not follow, because there is no server holding them.
- No tracking scripts. No analytics, no session recording, no fingerprinting. The advertising is the only third-party code.
- No paywall. The whole game and every article are free; advertising pays for the hosting.
Who makes it
An independent project, built and maintained by one person who plays too much sudoku and got tired of hints that only give answers. Corrections are genuinely welcome — if an explanation does not hold up on the board, that is a bug worth fixing.
See the contact page for how to report one.