Mochi Sudoku

About Mochi Sudoku

Mochi Sudoku is the timeless Japanese number-placement puzzle dressed in candy. Each board is a square grid split into smaller boxes, pre-seeded with a scatter of glossy given numbers, and your job is to fill every empty cell so that each number appears exactly once in every row, once in every column, and once in every box. Nothing is added or multiplied - sudoku is pure logic, a process of looking at what a row, column and box already contain and deducing what is still missing. The grids start tiny and friendly at 4x4, grow to a roomy 6x6, and build all the way up to the full 9x9 that sudoku is famous for.

You never type on a keyboard or hunt for a tiny cell. You pick a number up from the pad beneath the board and it stays in your hand, so you can tap cell after cell to drop it wherever it belongs - and the instant you pick a number, every cell already holding it lights up so you can see where it still has room. Tap a cell that already shows that number to lift it back out, or pick up the erase chip and tap cells to wipe them. You can also tap any cell on its own to light up its row, column and box and see exactly what it shares. Given numbers from the puzzle are locked and shown in bright white so you always know which ones are yours to change. The moment a number you place clashes with the same number already sitting in its row, column or box, both glow red, so a mistake is caught the instant you make it instead of unravelling twenty moves later.

Every board is no-fail and built to be fair. There are no timers and no lives - you can erase, rethink and refill as often as you like - and crucially every single puzzle is generated to have exactly one solution, so there is always a clean path of pure deduction to the end with no guessing required. If you get truly stuck, a Hint in the settings panel fills one correct cell for you, and Clear wipes your entries back to the original givens. Place the final number correctly and the grid celebrates with a flash, a little shake, sparkles and a five-note jingle before the level card slides in with three stars.

Want to get better? Read our full How to Solve Sudoku guide.

How to play Mochi Sudoku

1. Look at the candy grid: some cells already hold bright given numbers - those are fixed clues you build around.
2. Tap a number on the pad below the board to pick it up - its chip glows and every cell already holding that number lights up.
3. Tap any empty cell to drop that number in; it stays picked, so keep tapping cells to place it again and again.
4. Tap a cell that already holds the picked number to lift it back out, or pick up the erase chip and tap cells to wipe them.
5. If a number turns red it clashes with the same number in its row, column or box - clear it and try another.
6. Work through the board until every row, column and box holds each number exactly once; it then completes on its own, awards three stars, and offers Next.

Controls

Tips & strategy

• Hunt for the most-filled rows, columns and boxes first - a line that already has most of its numbers often leaves just one cell where a missing number can legally go.
• Pick a single number and sweep the whole board for it: see which boxes still need that number, then narrow down its cell by ruling out the rows and columns that already use it.
• Use the highlight - pick a number up from the pad and every copy of it lights up, making it easy to sweep that one number across the board and see where it still has room.
• A cell whose row, column and box together already show every number but one must be that missing number; these 'forced' cells are the safe moves that open up the rest.
• Lean on the red clash warning while learning: place a candidate, and if it lights red you have instantly learned it cannot go there.
• Smaller 4x4 and 6x6 boards are perfect for learning the logic before you tackle the full 9x9 in the later worlds.
• Stuck with no safe move in sight? Tap Hint in settings to reveal one correct cell - often that single number is enough to unlock a whole region.

Game features

• Real sudoku rules with a touch-native pen flow - pick a number once and tap it across the whole board, no keyboard, no fiddly typing, perfect for phones and tablets.
• 20 hand-tuned levels across five candy worlds - Berry, Citrus, Mint, Ocean and Galaxy - ramping from a gentle 4x4 through 6x6 up to the full 9x9.
• Endless mode past level 20 that generates fresh 9x9 boards forever, thinning the givens as the number climbs so the puzzles keep getting tougher instead of repeating.
• Every board is generated with a guaranteed unique solution, so there is always a clean line of pure logic to the finish and never a need to guess.
• Instant red-clash feedback the moment a number repeats in a row, column or box, plus a tap-to-highlight any number across the whole grid.
• Friendly no-fail flow: no timers or lives, erase and refill freely, a one-tap Hint that fills a correct cell, and Clear to reset to the givens.
• Soft candy art, per-number chime, and a sparkly five-note victory with flash and shake on every solved grid.
• Saved progress and three-star wins per level in a level-select grid, kept privately in your own browser with a one-tap mute.

The Number That Stays In Your Hand

What sets Mochi Sudoku apart from the wall of free sudoku apps is one quiet decision about input. There is no tap-a-cell then hunt-the-keypad shuffle: you lift a number off the pad once and it stays in your hand, so a single digit can be swept across the entire grid in one run, cell after cell. The board answers as you go. Every cell already holding that number softly lights up, the chip on the pad dims once that number is fully placed, conflicts flare red the instant they happen, and your own entries sit in a muted sage green that never gets confused with the locked white clues.

The detail worth singling out is the patient hint hand. Idle for six seconds, or stamp a short run of clashing or no-progress taps, and a finger drifts up and bobs over one cell, never naming the number, only pointing at where the logic actually bites. It looks for a naked single, the cell with exactly one legal answer, and if none exists it falls back to the tightest squeeze on the board, so the help teaches rather than solves. For more scaffolding there is an optional pencil-notes mode that paints every empty cell with its live candidates, and the same spotlight reaches into those marks too, glowing the candidate that matches the number in your hand.

The climb is a gentle on-ramp, not a difficulty wall. You start on four-by-four grids where the single rule lands in a minute, move to roomier six-by-six boards, then reach the full nine-by-nine, with the given clues thinning steadily across the Berry, Citrus, Mint, Ocean and Galaxy worlds, each carrying its own colour and a quietly twinkling starfield behind the board. Every puzzle is dug out of a complete random solution and verified by a counting solver to have exactly one answer, so a clean line of pure deduction always exists and guessing is never the intended route.

This fits an unhurried mood: no timer, no lives, freedom to erase and rethink as often as you like, with a one-tap Hint in settings that reveals and locks a single correct cell when you are truly stuck. It is a fine puzzle to hand a kid still learning the numbers are just nine symbols and the game is never arithmetic. Small touches keep it warm, each placed digit chiming a touch higher than the last, and a solved grid setting off a flash, a shake, a spray of sparkles and a five-note jingle. Endless mode then keeps building fresh nine-by-nines with ever-fewer clues, so the ceiling never quite arrives.