Sudoku Fog is fog-of-war Sudoku: every number you place correctly lifts the fog from the board. Play classic Sudoku, Killer Sudoku, Thermo Sudoku and 13 Sudoku variants, then mix two rule sets on one grid with hybrid puzzles.

HOW FOG SUDOKU WORKS
• Place the right number → fog lifts from that cell and its neighbours
• The sharper your solve, the more of the board you uncover
• Wrong moves keep the fog in place — no free reveals
• Clear the whole board to lift all the fog and lock in your time

NEW: KILLER SUDOKU
Killer Sudoku comes to the fog. Each dashed cage shows a sum: the digits inside the cage add up to it, with no repeats. Play Killer Sudoku on its own, or in hybrid puzzles with Renban or German Whispers.

13 SUDOKU VARIANTS
Each variant adds one new rule to classic Sudoku:
• Killer Sudoku — digits in a cage add up to its sum
• Thermo Sudoku — digits rise along every thermometer
• Kropki — white dots join consecutive digits, black dots join a digit and its double
• Arrow — the circle equals the sum of its arrow
• XV — X marks pairs that sum to 10, V marks pairs that sum to 5
• German Whispers and Dutch Whispers — neighbours on a line stay far apart
• Renban, Consecutive and Odd/Even
• X-Sudoku, Anti-Knight and King's Move

HYBRID PUZZLES
Combine Sudoku variants on one grid. Hand-picked hybrid puzzles such as Renban + Killer, German Whispers + Killer and German Whispers + Kropki make you reason with two rule sets at once. A hybrid opens as soon as you hold both of its variants.

King's Move and Odd/Even are free. Unlock the other variants with points you earn from Hard wins, daily challenges and streak milestones, or get them all at once with Pro.

DAILY SUDOKU CHALLENGE
A new puzzle every day at midnight UTC, the same for every player worldwide. Solve it, beat your best time and keep your streak alive. On weekends, take on a special Masterpiece puzzle.

GLOBAL LEADERBOARDS
Compete on Best Times, Hardcore, Career and Streak boards, plus a weekend Hall of Fame. No email or sign-up: just pick a nickname.

CULINARY JOURNEY
Travel the world through Sudoku. Complete countries to unlock neighbouring regions, discover beautifully illustrated local dishes, and build your gourmet gallery across 10 countries.

MORE
• Offline Sudoku — no connection needed for the puzzles
• Smart Notes — auto-updating pencil marks that prune themselves as you solve
• Smart Hints — a gentle focus nudge first, then a fill when you're truly stuck
• Achievements — dozens to earn as you master the fog
• 9 languages — English, 繁體中文, 简体中文, 日本語, 한국어, Français, Deutsch, Español, Português
• Dark mode — light, dark, or follow system

CLEAN & MINIMAL
No countdown timers forcing you to rush. No energy bars. No pop-ups mid-puzzle. Just you and the fog.