Sudoku online expert level of the game is suitable for players with a high level of experience in Sudo Ku puzzles. Sudoku expert level is not your regular game and can be conquered by proficient techniques and advanced strategies.
Basic Sudoku rules still apply for Sudoku expert puzzles, as:
The game still has the same amount of digits, rows, columns, and 3x3 grids.
Each digit can still be used only once in each row, column, or small square.
The total value of each region is 45
But let’s see what is different about an expert online sudoku puzzles.

You are challenged with the higher complexity of digit placement in the grid
Basic Sùdoku strategies won’t solve the puzzle and you need to come up with better solutions
You can play with or without hints, but even experienced users sometimes don’t manage to finish the grid hint-free
Most grids require Forced entry, Digit-by-digit, Guess-Procced, and Tripple sell techniques, that are mastered only by experienced players. The secret is knowing which one and at what point of the game to use.
You need to be ready to spend more time on it. Solving expert online Sudoku for free requires more time in comparison to other levels.

There is no trick that can help you become an expert Sudoku puzzles solver. As the key to being a skilled player is practising more playing Sudoku Pro and having fun in the process.
You don’t need to pressure yourself to do 10 grids a day if you don’t want to. Enjoy the process, be curious about learning new advanced techniques and strategies and your achievements will follow!