Free online Sudoku

Sudoku

Play free online Sudoku with notes, hints, keyboard controls, and automatic progress saving. Choose easy, medium, hard, or expert puzzles and continue anytime with no download.

Unique solution Auto-save Hints & notes No download Shareable puzzle ID
Time 00:00
Mistakes 0/3
Progress 0/81
Puzzle ID --

Select a cell, then choose a number.

Find the right Sudoku tool

Popular Sudoku searches this site supports

Different players arrive with different goals: some want a clean online board, some need a next-step hint, and others want paper puzzles with answers. These shortcuts keep each search intent one click away.

Online play

Free online Sudoku with notes

Use notes, hints, undo, mistake checking, and keyboard controls directly in the browser.

Play no-download Sudoku
Need help

Sudoku solver step by step

Paste or type a puzzle, then reveal a logical next hint or solve the grid with explanation.

Open the Sudoku solver
Paper puzzles

Printable Sudoku with answers

Generate easy, medium, hard, or expert Sudoku sheets with optional answer keys and large print.

Create printable Sudoku
Worksheets

Sudoku worksheets for classrooms

Print easy Sudoku worksheets with answer keys for students, kids, and screen-free logic practice.

Open Sudoku worksheets
Daily habit

Daily Sudoku puzzle online

Return for today's puzzle, keep a local streak, and replay the same date-based challenge.

Play today's Sudoku
Picture logic

Free online Nonograms

Try picture logic puzzles with printable sheets, large-print layouts, and a step-by-step Nonogram solver.

Play Nonograms
Cross sums

Free online Kakuro puzzles

Play cross sum number puzzles, print Kakuro worksheets, or use the sum combination solver.

Play Kakuro

Achievements

Local best times

    4 difficulty levels
    3 mistake limit
    9x9 classic grid
    0 downloads needed

    How to play Sudoku

    Fill the 9 by 9 grid so every row, column, and 3 by 3 box contains the numbers 1 through 9 once. Use notes when you are unsure, then remove candidates as the puzzle opens up.

    Beginner solving tip

    Start with rows, columns, or boxes that already contain many numbers. If only one digit can fit an empty cell, place it; if several digits can fit, add notes and come back later.

    Choose the right Sudoku difficulty

    Easy Sudoku puzzles are best for warming up and learning the rules. Medium puzzles need more notes and scanning. Hard and Expert puzzles require patient candidate tracking and stronger solving patterns.

    Use notes without slowing down

    Notes are most useful when a cell has two or three possible numbers. Avoid filling every empty square with every candidate; too many notes can make the grid harder to read.

    Online Sudoku controls

    Select a cell, then tap a number. On desktop, use the number keys to enter digits, arrow keys to move around the grid, Backspace to erase, and N to toggle Notes mode.

    Hard and Expert Sudoku practice

    Hard and Expert puzzles are easier to enjoy when hints reveal one safe move at a time. The verified puzzle bank now includes advanced practice puzzles with shareable IDs and technique labels such as Naked Pair, Hidden Pair, Pointing Pair, and X-Wing.

    Share a Sudoku puzzle by ID

    Every bank puzzle has a stable ID such as SDK-0GJO60B. Share a link like /play?id=SDK-0GJO60B, or share result text like I solved Sudoku SDK-0GJO60B in 5 minutes, so another player can open the exact same grid.

    Kakuro cross sum puzzles

    For players who like Sudoku-style digit logic with arithmetic clues, the new Kakuro section adds online play, printable Kakuro puzzles, and a sum combination calculator.

    Sudoku FAQ

    What is the goal of Sudoku?

    The goal is to complete the grid so each row, column, and 3 by 3 box contains every number from 1 to 9 exactly once.

    Is this Sudoku free?

    Yes. The puzzle is playable in the browser with no download or account required.

    Why use notes?

    Notes help you track candidate numbers before you are certain about a cell. They are especially helpful on medium, hard, and expert puzzles.

    Does each Sudoku have one solution?

    Generated puzzles are checked by the Sudoku engine before play, so each published grid is intended to have a single valid solution.

    Can I continue an unfinished Sudoku later?

    Yes. The current puzzle, timer, notes, mistakes, and progress are saved in this browser so you can return later and continue the same game.

    Can I share a Sudoku puzzle by ID?

    Yes. Use Copy puzzle link to share a stable link like /play?id=SDK-0GJO60B, so another player can open the exact same Sudoku grid.