Welcome · Step 1 of 5
What is Sudoku? 🧩
Sudoku is a number puzzle on a 9×9 grid. Fill every empty square with a number from 1 to 9. No math — just logic!
The grid has three groups:
→ 9 Rows (left to right)
→ 9 Columns (top to bottom)
→ 9 Boxes (the 3×3 squares)
The Rule · Step 2 of 5
No Repeats! 🚫
Every row, column, and 3×3 box must contain the numbers 1–9 exactly once. That's the only rule!
1 2 3 4 5 6 7 8 9 ✅ Correct
1 2 3 4 5 6 7 3 9 ❌ 3 appears twice
How to Solve · Step 3 of 5
Use Elimination ✏️
Look at an empty cell. Check its row, column, and box. The numbers already there cannot go in that cell. What's left is your answer!
Row has: 1 3 5 7 8 9
Column has: 2 6 · Box has: 2 4 6
Only 4 is unused everywhere → Answer is 4 ✅
Your Guide · Step 4 of 5
Follow the Yellow Square! 🟡
On Easy and Medium, the yellow highlighted square shows the best cell to fill next. The blue coaching bar above the board explains exactly what to do! On Hard and Expert, you're on your own — that's the challenge.
Tap the yellow square → enter the missing number!
Earn Your Rank · Step 5 of 5
Aim for S+ 🏆
When you finish a puzzle, you get a rank based on how many errors you made. Fewer errors = higher rank. Ranks unlock bonus XP and get tracked in your profile.
S+ · 0
S · 1-2
A · 3-5
B · 6-10
C · 11-20
D · 21+
Difficulty: Easy → Expert. Higher levels have fewer clues.
Daily: a fresh date-seeded puzzle, one per day.
Notes / Auto: add pencil marks. Auto fills the obvious ones (off on Hard / Expert).
Hint: reveals one cell (3 per game; off on Expert).
Check: shows if you've made any wrong moves.