Sudoku

Fill the grid so every row, column and box has each digit once.

Rules

  1. Every row and every column has each digit once.

    1234341221434321
    ✓ No repeats
    1234123434124321
    ✗ Column repeats
  2. Every box (heavy lines) has each digit once.

    1234234134124123
    ✗ Box repeats

Example: Warm-up

2421
The puzzle
1423321423414132
Solved

Playing here: Tap a cell, then a number (or type it). Pencil adds small notes.

Play Warm-up