Medium·31 givens
·0 mistakes
·0:00
- 1–9
- Fill the selected cell
- Shift+1–9
- Pencil a note
- N
- Notes mode on or off
- ⌫ 0
- Erase
- Z
- Undo
- H
- Hint
- M
- Music on or off
- S
- Next song
- ←↑→↓
- Move around the grid
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Puzzles solved: 1
Solve a Hard puzzle to record your time, mistakes and hints.
Solve an Expert puzzle to record your time, mistakes and hints.
The board is a 9×9 grid made of nine 3×3 boxes. Some squares already hold a number: the givens, printed in black. Fill every empty square with a number from 1 to 9 so that:
This row has 1, 2, 3, 4, 5, 6, 8 and 9. The only number missing is 7, so the empty square must be 7.
A short tutorial. Try each step on an Easy puzzle; the same ideas carry you all the way to Expert.
Fewer empty squares means fewer possibilities. A row with eight numbers filled tells you the ninth straight away.
Pick a number, say 5, and tap it on the pieces: every 5 on the board lights up. Each row, column and box can hold only one 5. Look at a box without a 5 yet and cross out the rows and columns that already have one. Often only one square is left.
Rows and columns that already have a 5 are crossed out. Only one square is left, so the 5 goes there.
Look at one empty square and ask: which numbers are already in its row, its column and its box? If eight of the nine are taken, the ninth is the answer. Tap the square, then tap the piece.
Turn Notes on and tap the pieces to pencil small candidates into a square. When a square has only one candidate left, it’s solved. With Clear notes when a number is placed on, your notes tidy themselves as you go.
Sometimes a square has several candidates, but one of those numbers can go nowhere else in the row, column or box. Then that square is its only home. Notes make this easy to see.
Hint fills in one correct number, Undo takes back a move, and Erase clears the selected square. On Hard and Expert, hints and mistakes are counted in your Records, so try to think it through first.
Every puzzle here can be solved by logic. If you feel like guessing, go back to scanning: there is always a square you can be sure about.
Medium has fewer givens. Hard and Expert come with the full game, and that’s where the clock, best times and the two slow songs come in.
1–9 places a number, Shift+1–9 pencils a note, arrow keys move, N switches notes, Z undoes, H gives a hint, M turns the music on or off, S skips a song, Backspace erases.
In your browser, Easy and Medium are free to play, with no time limit and no account. Your games and records stay in this browser.
Hard and Expert come with the Bill’s Sudoku app for iPhone, iPad and Mac: free for 30 days, then a single one-time purchase. Android is coming soon. Get it on the App Store.
Email [email protected] and say which device you use, or visit the support page.
Version 1.1
Bill’s Sudoku is a calm, classic Sudoku with a Japanese touch: a wooden board, shogi-style number pieces, indigo wave cloth and gentle café jazz. It was made for one person who loves a quiet puzzle.
Every puzzle is generated on your device and has exactly one solution. The music is original: five tunes played live by a small virtual band (electric piano, upright bass, brushes and vibraphone) that your phone, tablet or computer performs as you play, so no two sessions sound quite the same.
© 2026 Paul Allan Manacap. Sudoku is a classic number-placement puzzle; the Japanese name 数独 means “the digits must be single”.
Bill’s Sudoku collects no personal data. There is no account, no sign-in, no analytics and no advertising.
Because we hold no data about you, there is nothing for us to access, correct or delete on your behalf. Your own data is in your hands: to erase everything, delete the app. To ask a question or exercise a right under the laws of your country, email [email protected].