Fast paste solver

81 Digit Sudoku Solver

Paste an 81 digit Sudoku string, using 0 or dots for blanks. The solver will fill the grid, validate the Sudoku string, check conflicts, solve it, or reveal one next-step hint.

Paste 81 characters 0 or dots for blanks Next-step hints Sudoku conflict checker

Paste 81 characters into the text box, or type digits into the grid.

Paste your 81 digit Sudoku here

Use 1-9 for clues and 0 or dots for empty cells. Spaces and line breaks are ignored, so you can validate a Sudoku string copied from another site.

Vetted sample bank

Try a high-quality 81 digit puzzle

Choose a checked puzzle from the static sample bank, then solve it, ask for a next hint, or copy the 81 digit string.

Level Sample puzzle

Sample metadata will appear here.

81 digit format

Read rows left to right. Use 1-9 for given numbers and 0 or a dot for empty cells.

Solving steps

81 character input

How to format an 81 digit Sudoku puzzle

An 81 digit Sudoku string is just the full grid written row by row. This format is common because it is easy to copy from another solver, puzzle database, book notes, or generator.

Start at the top-left cell. Read the first row from left to right, then continue row by row.
Use digits for clues. Enter 1 through 9 for numbers already printed in the puzzle.
Use 0 or dots for blanks. Empty cells can be written as 0 or as a period.
Paste exactly 81 cells. Extra spaces, line breaks, and punctuation are ignored, but the final puzzle should describe all 81 cells.

Example 81 digit Sudoku

You can paste this sample into the text box to test the solver.

530070000600195000098000060800060003400803001700020006060000280000419005000080079

Paste 81 digit Sudoku solver

The text box is built for fast input. Paste the full 81 digit Sudoku string, and the grid updates automatically so you can solve, check, or ask for a hint.

Vetted Sudoku test puzzles

The sample bank includes checked 81 digit puzzles across easy, medium, hard, and expert levels. Each sample has one solution and difficulty metadata.

Sudoku conflict checker

If a row, column, or box has a duplicate clue or conflict, the solver reports the problem before attempting to solve the puzzle.

Validate Sudoku string

Paste a copied puzzle to check whether the 81 characters describe a legal Sudoku grid before spending time solving or printing it.

Need manual input?

If you prefer typing into cells, use the regular step-by-step Sudoku solver with the same grid controls.

Use 81 digit examples for practice

Teachers and puzzle makers can paste a sample, verify it, then print related practice sheets from the Sudoku classroom worksheets page.

81 Digit Sudoku Solver FAQ

How do I paste an 81 digit Sudoku puzzle?

Paste 81 characters into the text box, reading the Sudoku grid left to right and top to bottom. Use digits 1 to 9 for clues and 0 or a dot for empty cells.

Can I use dots instead of zeros for blanks?

Yes. The solver accepts dots and converts them to blank cells in the grid.

Can the 81 digit solver give only one hint?

Yes. Use the Next hint button to reveal one safe move with an explanation instead of solving the entire Sudoku.

Why is my 81 digit Sudoku invalid?

Use the Sudoku conflict checker to validate the Sudoku string. The puzzle may be invalid if a digit repeats in the same row, column, or 3 by 3 box, or if the starting clues create a contradiction.

Can I validate a Sudoku string before solving?

Yes. Paste the 81 characters and use the page as a validate Sudoku string tool before you solve, copy, or print the puzzle.