Solid Sudoku: Daily Puzzle

A sudoku, not a platform.

Solid Sudoku is a classic 9x9 sudoku with a daily challenge — a calm, paper-styled logic puzzle, fully playable offline. Open the app, pick a difficulty, play.

Try everything free for 7 days. One small unlock keeps the whole game. No ads, ever. Nothing else to buy.

A REAL LOGIC PUZZLE

Every puzzle is generated on your device and always has exactly one solution — a real brain game, solvable by deduction, never by guessing. Four difficulty levels run from a gentle Easy to a properly stubborn Expert.

DAILY CHALLENGE

One sudoku a day, identical for every player in the world. Solve today's grid and see how your time stacks up — an anonymous percentile against everyone else who played. No account. No usernames. Just the number. Keep a streak going on the calendar — a day counts at any difficulty, so your streak is about showing up, not about speed. An optional daily reminder keeps it alive.

THE TOOLS YOU'D ACTUALLY USE

• Notes mode for pencil marks — cleared automatically when you fill the cell
• 3 hints per game. A hint adds 30 seconds to your adjusted time, so a solved grid still means something
• Full undo and redo — the move history even walks back hints and mistakes honestly
• Optional error highlighting — flag wrong entries and rule conflicts, or switch it off and trust your logic
• Smart highlighting for the selected row, column, box, and matching numbers
• The number pad counts down how many of each digit are left

DESIGNED LIKE PAPER

The whole aesthetic is called Clean Paper: a warm white page, clues that look printed, your entries in soft blue ink. A fresh puzzle page every game, with a touch of retro pixel charm at launch.

NO INTERNET REQUIRED

Fully playable offline. On a plane. In a basement. Puzzles are generated on your device — no WiFi, no cellular, no waiting for a server. Even today's Daily Challenge works offline; only the percentile needs a connection. Your game saves itself and resumes exactly where you left off. Offline sudoku, start to finish.

ONE HONEST UNLOCK

The whole game is free for 7 days — every difficulty, every tool, nothing held back. If it earns a spot on your home screen, one unlock keeps it: a small yearly subscription or a one-time lifetime purchase. No ads, ever. Nothing else to buy. No account, no sign-in — purchases use anonymous store IDs, there's no ad tracking, and your data is never sold.

A LITTLE STOIC CALM

Stoic quotes from Marcus Aurelius, Epictetus, and Seneca rotate through the app. A small moment of philosophy before the logic starts.

SUDOKU FEATURES

• Classic 9x9 number puzzle with four difficulties: Easy, Medium, Hard, Expert
• Daily Challenge — the same seeded puzzle for everyone, every day
• Unique-solution puzzles, generated instantly on device
• Pencil marks, hints, undo/redo, error checking
• Pause-aware timer — pausing never costs you time
• Three mistakes and the round is over — gentle stakes, honest wins
• Auto-save and resume across launches
• Works with a hardware keyboard — arrows, digits, shortcuts
• Streak calendar with an optional daily reminder
• Number lock — pin a digit and place it across the grid
• Remaining counts under every digit on the number pad
• Statistics dashboard — win rate, streaks, solve-time trend
• Dark and light themes, plus a high-contrast mode

The whole game, right here. Pick a difficulty. Fill the grid. That's it.