Clean Sudoku Modern

A free sudoku built to get out of your way.
Most sudoku apps treat your screen like a billboard: banner ads,
full-screen interstitials, energy timers, paywalls, hint counters
that nag you to buy more. Clean Sudoku takes the opposite approach.
Open the app, pick a difficulty, play. That's it.
WHAT'S INSIDE
• 300,000 puzzles across Easy, Medium, and Hard
• No in-app purchases, no account required
• Plays fully offline
• Dark mode
• Your in-progress puzzle auto-saves — pick up exactly where you left off
A SMARTER HINT BUTTON
Most sudoku apps' "hint" just fills in a square for you. That's a cheat.
Clean Sudoku's hint shows you the deduction behind the move — step
by step, with highlighting. Stuck on a Hidden Single? It points out
the row, shades the cells where the digit can't go, then reveals
where it must go. As puzzles get harder, the same engine teaches
Naked and Hidden Pairs, Locked Candidates, X-Wings, Swordfish,
Y-Wings, Skyscrapers, X-Chains, and more. Tap Hint a second time on
the same board and it advances to a different technique — so you
actually learn, instead of unlocking the answer.
QUALITY-OF-LIFE
• Long-press any digit to highlight where it lives and where it can't go
• Pencil-mark notes that auto-clear when peers get filled
• Undo any move (or a whole hint, if you change your mind)
• Optional real-time conflict highlighting
• Per-puzzle stats: time, score, mistakes, hints, highest technique reached
• Aggregate stats per difficulty: best time, best score, totals — stored on-device
A WORD ON THE DESIGN
The app is one screen. The grid is one screen. Settings has four
toggles. The pause menu has one button. When you finish a puzzle,
you see your score and start the next one. No "rate us" popups,
no daily streak guilt-trips, no celebration animations to dismiss.
If that's the sudoku you've been looking for, it probably is.