Hard Sudoku.
One grid, a little challenge, and the satisfaction of figuring it out your way.
A way to approach this level
In a hard grid, some deductions remove candidates without immediately placing a digit. Look for naked pairs and relationships between boxes and lines. A justified elimination can create a single several moves later.
This level’s evaluator includes locked candidates and pairs as well as singles. Work with complete pencil marks and keep track of the reason behind each elimination. Hints may reveal a direct step when the required technique is not yet covered by the explainer.
Your next move starts here.
Small lessons. Clear examples. More “I’ve got it” moments.
How to play sudoku: Rules and first steps
Learn classic sudoku rules, recognise rows, columns and boxes, and solve your first cells with worked examples.
Read & practiseNaked single: One cell, one candidate
Find cells with just one candidate and learn to check why the other eight digits are excluded, without guessing.
Read & practiseHidden single: One digit, one possible place
Learn to find the only place for a digit in a row, column or box, even when the cell has several pencil marks.
Read & practiseEvery player has something to share.
A space for your questions, discoveries and little victories.
A little more curiosity.
A sudoku routine that does not depend on the clock
A simple way to practise deliberately, review a deduction and enjoy a puzzle without always chasing your fastest time.
Read & practiseSudoku pencil marks: When they help and when they confuse
Organise sudoku notes, distinguish complete candidate lists from reminders and avoid deductions based on missing pencil marks.
Read & practiseWhat makes a daily sudoku challenge comparable
Why a shared puzzle needs clear rules for difficulty, assistance, pauses and repeat attempts to make a leaderboard meaningful.
Read & practise