Free Sudoku Online

What you do

A cozy sudoku game with the classic rules and real digits. There are 600 puzzles, 120 at each of five difficulties, and every one has exactly one solution that you can reach by logic alone, without guessing. The difficulty says which techniques you need: Gentle puzzles fall to cells with only one digit left, Easy ones ask you to find the one place a digit fits, Medium adds pairs, pointing and box-line reduction, Hard adds triples and the X-wing, and Expert adds the swordfish and the XY-wing. Stuck? The Hint button finds the easiest next step on your board and explains it in a sentence, such as which row needs a 7 and why only one cell can take it. Each solved puzzle plants a flower in your garden, a different flower for each difficulty. There are no lives, no mistake limits and no streaks. Your puzzles and garden save on this device.

How to play

1. Pick a difficulty on the menu and press New puzzle (or Continue), or play today’s sprout, a Medium puzzle that changes every day.
2. Fill the grid so every row, every column and every 3x3 box holds the digits 1 to 9 once each. The dark digits belong to the puzzle and cannot change.
3. Select a cell, then press a digit on the number pad. The small number on each key shows how many of that digit are still to place.
4. Turn on Notes to pencil in small candidates instead. Placing a digit removes it from the notes in the same row, column and box. Auto fills every empty cell with its candidates.
5. A digit that repeats in its row, column or box is always marked. Turn on Check against the solution in the menu to also mark digits that do not match the solution.
6. Hint explains the next logical step and highlights the cells involved; press it again to do that step. Each solved puzzle plants a flower in your garden.

Controls

• Keyboard: arrow keys move, 1 to 9 place a digit (Shift with a digit writes a note), Backspace, Delete or 0 erase, N switches notes, Z undoes, Y redoes and H gives a hint. Escape closes a hint or the garden.
• Touch or mouse: tap a cell, then a digit key. Erase is on the number pad, and Undo, Redo, Notes, Auto notes and Hint are in the row of tools.
• Toolbar: pause, help, restart (starts the puzzle on the board over; your garden and records stay), optional sound and fullscreen.

Tips worth knowing

• Start with the digit that already appears most often. The small counts on the number pad show which digits are nearly done.
• Scan one box at a time for a digit it still needs. If the rows and columns crossing the box rule out every cell but one, that is where it goes.
• Use notes once singles run out. Pairs, pointing and box-line reduction only show up when you can see the candidates.
• A hint on its first press only explains. Read it, look at the highlighted cells, and try the step yourself before pressing Hint again.
• Solve one puzzle at each difficulty to plant every kind of flower. Gentle grows daisies, Easy tulips, Medium sunflowers, Hard bluebells and Expert roses.

Accessibility

• Everything can be played with a keyboard: arrow keys move around the grid, 1 to 9 place digits, and every button is reachable with Tab.
• There is no time pressure. The timer only records how long a puzzle took, and it stops whenever the game is paused or hidden.
• Digits are large on a high-contrast grid with thick box lines. Conflicts and checked mistakes are shown with color and an underline or dot, not color alone, and every cell has a spoken label.
• Hints are written in plain words and announced to screen readers along with each placement.
• Reduced motion skips the bloom animation and card transitions. Sound is optional and never needed to play.

Guides and roundups

• How to Play Sudoku: Rules, Techniques and Hints
• Free Online Games for Seniors and Older Adults
• Best Cozy Puzzle Games to Play in 2026