Easy puzzles fall to singles alone — cells with only one possible digit, or digits with only one open cell left in a row, column, or box. You'll never need to track candidates across the whole grid or hold two possibilities in your head at once; every step here is a straight read of what's left. That makes it the right place to learn sudoku's actual mechanics, or to warm up before a harder puzzle. New to the rules? See how sudoku works.
Ready for more? Medium is one step up.