Play Sudoku Online for Free

SudokuIt lets you play free Sudoku puzzles online in Easy, Medium, Hard, Expert, Master, and Extreme difficulties.

Whether you're just starting out or solving advanced puzzles with ease, we offer a wide variety of sudoku games for every skill level. Practice free sudoku online anytime and boost your logical thinking on SudokuIt.com.

History of Sudoku

Sudoku, meaning "single number" in Japanese, is a logic-based puzzle that originated from a number placement game invented in the late 1970s. It gained worldwide popularity in the early 2000s and remains a favorite pastime for millions due to its mix of simplicity and challenge.

Sudoku Games for Every Level

At SudokuIt.com, you'll find puzzles to suit your current skill level, from first games that need nothing but singles to long solves that need advanced patterns. Our solver grades each puzzle before it is published.

How SudokuIt Grades Its Six Levels

The solver works through a puzzle one step at a time, using techniques a person can learn. Each technique has a difficulty score, and the hardest step in the solve sets the level. Givens, the digits printed at the start, count only at the low end of the scale: there, a puzzle with 28 or more is Easy and one with fewer is Medium.

Here is what our solver found in the 3,177 published puzzles we measured in October 2026:

Easy: 30 givens, every time. In 96% of these puzzles, singles are all you need: a hidden single or a last possible number.
Medium: 20 to 23 givens, most often 23. In nearly two of three, the hardest step is still a single. For another one in four, it is a pointing pair or a claiming group.
Hard, Expert, Master and Extreme: most start with 21 to 23 givens (1,146 of 1,150 puzzles). The hardest step comes from subsets (pairs, triples and quads), coloring, wings and fish, the pattern family that X-Wing belongs to. Extreme puzzles can need several of these in one solve.

Our technique guides walk through most of these patterns on real boards, from singles to wings and fish.

Tips to Get Started

Start with the easiest number: Look for numbers that already appear the most in the grid. Begin by filling in obvious gaps in rows, columns, or boxes.
Use pencil notes: Keep track of possible numbers in each cell: this makes solving complex puzzles more manageable and helps avoid mistakes.

New Challenge Every Day

Looking for a new puzzle each day? Our daily sudoku section posts one. Its calendar keeps earlier days open, and when you are logged in it marks the days you have solved.

How to Play Sudoku

The goal of sudoku is to fill a 9×9 grid so that every row, column, and 3×3 box contains the digits 1 through 9, with no number repeated in the same row, column, or box.

The rules are simple:

Each puzzle starts with some numbers already filled in.
Each row must include every number from 1 to 9 exactly once.
Each column must include every number from 1 to 9 exactly once.
Each 3×3 box must include every number from 1 to 9 exactly once.

You don't need math: just logic, patience, and observation.

Explore more information to improve your skills:

Sudoku Rules: learn the core principles behind the game
Solving Techniques: discover advanced strategies and logic methods

Start Playing Sudoku Today

Sharpen your logic, stay focused, and have fun with SudokuIt. Choose your difficulty, start solving, and enjoy the satisfaction of completing a puzzle, one number at a time.

Prefer paper? Print a puzzle and you get one puzzle on one page, with a short code next to the grid. Type sudokuit.com/p/ and the code, or scan the QR code on the sheet, and the same puzzle opens here as a game, with hints if you get stuck.

Start a Puzzle Now

What is SudokuIt.com?

SudokuIt.com is a modern, user-friendly sudoku platform where you can play sudoku in your browser, from a library of more than 3,000 sudoku puzzles. Our goal is to make sudoku accessible and enjoyable for everyone: from beginners learning the rules to experts mastering advanced solving techniques.