Sudoku Expert Online

Sudoku Expert Online - Play Online

Logic puzzle fan? Want 140 handcrafted levels? Sudoku Expert Online delivers three modes: classic 6×6, classic 9×9, and Killer Sudoku with cage sums. Desktop brain training at its finest.

How to Play Sudoku Expert Online

The goal is simple: fill every cell. Each row, column, and block must contain no repeated digits. In Killer mode? No given digits. Just cage sums as clues. Digits within a cage must be unique. Solve the grid. Earn stars. Repeat.

Master the Grid

Tap an empty cell. Pick a digit from the panel below. Fill the board. In 6×6 mode, grids are quick warm-ups. In 9×9 mode, difficulty scales from easy to expert. Killer Sudoku? Built-in helper shows remaining sum and possible digits for each cell. Use it. Save time.

Tools That Matter

Hit the ✎ button. Enter Notes mode. Pencil in candidates. Auto-cleanup removes invalid marks. Made a mistake? Press ↶. Unlimited undo. Conflict highlighting catches duplicates instantly. Same-number tracking lights up matching digits across the board. Smart tools. Zero guesswork.

Progression System

Complete levels. Earn stars. Unlock color themes and achievements. Daily challenge resets every 24 hours. New puzzle. Fresh stars. Progress syncs across devices. Start on desktop. Continue on mobile. Seamless.

Strategy Tips

Start with 6×6 mode. Learn the rhythm. Graduate to 9×9. In Killer mode, focus on small cages first. A cage with two cells and sum 3? Only 1+2 works. Lock it in. Use Notes mode to map all possibilities before committing. Conflict highlighting is your safety net. Trust it.

Key Features

• 140 Levels: Increasing difficulty. 6×6 quick grids. 9×9 expert challenges. Killer Sudoku cage puzzles.
• Smart Tools: Pencil marks with auto-cleanup. Unlimited undo. Conflict highlighting. Same-number tracking.
• Killer Mode Helper: Shows remaining sum and possible digits for each cell. Built-in logic assistant.
• Daily Challenge: New puzzle every day. Fresh stars to earn.
• Cross-Device Sync: Progress saves automatically. Play anywhere.
• Unlockable Themes: Earn achievements. Customize your board with color themes.

Who is Sudoku Expert Online for?

Perfect for puzzle veterans and logic newbies. Great for 5-minute brain breaks or hour-long deep dives. Desktop-only HTML5 game. No downloads. Click and play.

Release Date & Developer

Sudoku Expert Online was developed by Azatiys Games. Released April 14, 2026.

Controls

• Mouse Click: Select cell
• Digit Panel: Enter number
• ✎ Button: Toggle Notes mode
• ↶ Button: Undo last move