Troubleshooting and FAQ
Answers to the questions people ask most about Sudoku Solver.
It says only a few digits were recognised
The message Only … digits recognised — try a sharper photo and crop tightly around the grid. appears when it finds fewer than 10 digits. Try again with:
- More light, and no shadow from your phone across the page.
- The phone held flat above the puzzle, not at an angle.
- A sharp photo: hold still, and tap the screen to focus if your camera allows it.
- A crop that covers only the 9×9 grid.
If it still struggles, type the puzzle in by hand.
Some digits are wrong or missing
Text recognition is not perfect, especially with small print, handwriting or a curved page. Always compare the board with the puzzle before you solve. Tap a wrong cell and enter the right digit; tap the backspace key to empty a cell.
The grid has conflicts
Two digits in the same row, column or 3×3 box are the same, and both are shown in red. One of them was misread or mistyped. Fix it, then tap Solve.
This puzzle has no solution
The clues do not clash directly, but no complete solution exists. Usually a digit was misread (a 1 read as a 7, or an 8 as a 3). Check every clue against the original.
It says to enter at least a few clues first
The solver needs at least 8 clues before it tries. A real Sudoku always has many more; add the missing ones.
Can it read handwritten puzzles?
It is designed for printed puzzles. Handwritten digits may be misread, so check the board carefully or type the puzzle in.
Could not open camera or gallery
Camera hands over to your phone's camera app, and Upload to Android's photo picker. If one of them cannot open, check that your camera or gallery app is installed and turned on, then try again. Sudoku Solver itself asks for no permissions.
Does my photo get uploaded?
No. Recognition runs on the phone with Google ML Kit, and the temporary image is deleted after reading.
Can it give me a hint instead of the whole answer?
No. Solve fills in every empty cell at once.
Where do I report a problem?
Open an issue on the Sudoku Solver GitHub issues page.