fastsudoku Hints
Stuck on a puzzle? Enter it and get the next logical move explained — or try a random example and watch it solve step by step.
How to use this sudoku assistant
1. Enter your puzzle
Type the numbers you already know into the grid above, or pick a random example to get started.
2. Click the lightbulb
Each click reveals one logical move — the technique, the cell, and a plain-English explanation of why it works.
3. Learn as you go
Technique names link to in-depth guides. You solve your puzzle while building real sudoku skills — one step at a time.
Free fastsudoku hints · No sign-up · No download · Step-by-step logical reasoning
New to sudoku?
Learn the one simple rule, how the grid works, and how to play your first puzzle — in plain English.
What Is Sudoku? →