Stuck on a puzzle? Type it in and we'll show you the next move, one at a time. Each step says which technique you used. You learn while you finish.
The point of this tool isn't to finish your puzzle. It's to teach you the technique you missed. Use one step. Read what it tells you. Then keep playing.
If you just want the answer, use the plain solver instead. If you want to understand why you got stuck, you're in the right place.
Naked singles, hidden singles, naked pairs, pointing pairs, and box-line reduction. That's enough to finish every easy, medium, and hard sudoku, and most expert ones.
Your puzzle needs a chain technique (XY-wing, swordfish, coloring, forcing chains). Those aren't in this tool yet. For now, you can use the full solver to see the answer.
Not yet. clearing and starting over is the workaround. A back button is on the list.
Yes, if you read what each step says. The patterns repeat across puzzles. Once you recognise a hidden single by feel, you don't need this tool for it any more.