Separate entry errors from logic errors
If a board becomes inconsistent, validate the position before viewing the solution. That helps you distinguish a copied digit, an over-deleted candidate, and a real strategy gap.
After checking a position in solver, review the matching technique page to apply the same logic yourself.
Number Place Solver
Solver Guide
Use the solver as a review tool
This solver validates a position, solves the board, and explains a next step. For learning, the safest route is to check the input, inspect one reason, then return to the strategy guide instead of reading the full answer immediately.
Check only the next step first
A full solution removes most of the practice value. Start with the next-step hint, read the affected cell or candidate, and explain why that move is valid on your own board.
Return to the technique page
Use the technique name from the solver as a bridge back to the strategy guide. Compare the valid and invalid diagrams, then try another puzzle at the same level.
Before using the result
- The solver is a learning aid, not a shortcut for copying answers. Use it to inspect why a candidate can be removed.
- If the entered board differs from the original puzzle, the solution and hint will not match your intended problem. Recheck blanks and digits before trusting the result.
- When entering a puzzle from another source, respect that source and do not use this page as a way to republish someone else’s puzzle.