GRID ATELIER / 9 × 9 NUMBER STUDY
A Sudoku desk built around the grid
Open the Sudoku editor to work in a 9×9 board with nine 3×3 boxes, select one of four difficulties, record candidates, and switch between play and printable PDF output.
- 9 × 9 cells
- 9 boxes of 3 × 3
- 4 difficulty settings
The sheet: rows, columns, boxes
The board has 81 cells. A number is checked against its row, its column, and its 3×3 box; the generator uses the same three checks while filling a completed board.
- 81 cells arranged in 9 rows and 9 columns
- Bold dividers mark every 3×3 box
- A selected cell also relates its row, column, and box
Four starting studies
A new game starts from a filled board. The generator shuffles positions and removes values one at a time; a removal remains only when the solution counter finds exactly one solution.
EASY — Target: 35 removed cells
The easy setting uses a target of 35 removed cells.
MEDIUM — Target: 45 removed cells
The medium setting uses a target of 45 removed cells.
HARD — Target: 52 removed cells
The hard setting uses a target of 52 removed cells.
EXPERT — Target: 58 removed cells
The expert setting uses a target of 58 removed cells.
From a fresh board to a checked finish
Choose a difficulty or begin another game. Given values cannot be edited; select an empty cell, then enter a number with the on-screen pad or keys 1–9.
01 — Select a cell
Only empty, non-given cells can become the active cell.
02 — Place or erase
A final entry clears that cell’s notes. Backspace or Delete erases the active entry.
03 — Complete the board
Completion is checked cell by cell against the generated solution.
Pencil marks and visible controls
The editor keeps play actions beside the board rather than hiding them behind a menu. Its hint dialog explains a found single in a row, column, box, or cell when that pattern is available.
NOTES — Candidate marks
Notes mode toggles the numbers 1–9 in an empty cell as small candidates.
HINT — A filled clue with explanation
A hint writes one value, selects its cell, counts its use, and opens the accompanying explanation.
HISTORY — Undo, redo, erase
Entries and notes are stored in the board history. Ctrl/Cmd+Z undoes; Shift+Ctrl/Cmd+Z redoes.
FOCUS — Time and board view
The timer runs during play and can be paused. The board also provides a fullscreen control.
Progress and the score sheet
An unfinished game with time, an entered value, or a note is written to browser storage. On loading a saved game, note arrays are rebuilt as note sets and the timer remains stopped until play resumes.
PROGRESS — Saved unfinished board
Completed games remove the saved game-progress record; starting a new game also clears it.
STATISTICS — Four time slots
Games played, games won, current and longest streak, and one recorded time for each difficulty are kept in the statistics record.
SCORES — Optional name entry after completion
After a completed board, the editor can submit a name, time, difficulty, mistakes, and hints used; the leaderboard requests up to 10 entries for the chosen difficulty.
A separate printable sheet
The Print tab generates fresh puzzles rather than exporting the board currently being played. Choose a difficulty, count, page layout, page format, and whether solution pages are appended.
COUNT — 1 to 12 puzzles
The selectable counts are 1, 2, 4, 6, 8, 10, and 12. Generation clamps the count to a minimum of 1 and a maximum of 12.
LAYOUT — 1, 2, 4, or 6 per page
The page grid supports one, two, four, or six puzzles per page.
PAPER — A4 or US Letter
The PDF uses portrait A4 or US Letter. Solution pages are added only when the include-solutions setting is on.
Reading the editor’s checks
- Show Errors only changes whether a non-matching placed value is highlighted; the mistake counter still increments for a non-matching final entry.
- The counter shows mistakes out of three and displays the “too many mistakes” message when the count reaches three.
- A hint can place a value directly. Hints used are included in the completion summary and the optional score submission.
- The print workflow creates a PDF download and shows an error message when PDF generation cannot be completed.
More at the play table
These linked tools lead to their own interfaces and controls.
- Word Puzzle
Open the five-letter word interface.
- Picker Wheel
Open the list and wheel controls.
- Coin Flip
Open the two-sided flip interface.
Sudoku desk notes
How is the board organized?
It is a 9×9 board with 81 cells. Rows, columns, and nine 3×3 boxes are used for the placement checks.
Which difficulties are available?
Easy, Medium, Hard, and Expert. Their removal targets are 35, 45, 52, and 58 cells respectively.
What does Notes mode do?
It toggles numbers 1–9 as candidate marks in the selected empty cell. A final number clears notes from that cell.
What can a hint explain?
The editor looks for a naked single, then a single location in a row, column, or box; otherwise it can give a generated-solution value for an empty cell.
What is saved between visits?
An unfinished board with progress can be stored along with statistics. A restored game does not restart its timer automatically.
What are the printable PDF boundaries?
The Print tab offers 1, 2, 4, 6, 8, 10, or 12 puzzles, with a hard maximum of 12, and layouts of 1, 2, 4, or 6 puzzles per page on A4 or US Letter.
Take a seat at the grid
Choose a difficulty, work through the cells, and use the notes, hint, history, time, pause, fullscreen, statistics, or print controls that fit the current board.