# What is Sudoku and how to solve it?

Sudoku is one of the most popular puzzle games, along with puzzles such as crosswords, Japanese crosswords, and rebuses. In Sudoku, the playing field is a large 9 by 9 square. The large square is divided into smaller 3 by 3 squares.

Depending on the difficulty of Sudoku, the playing field may be randomly filled with numbers. The player's task is to fill the empty cells with numbers from 1 to 9, so that there are no repeating numbers in each row, column and in each small square.

On our website, you can play Sudoku online directly in your browser on your computer or smartphone without installing an application.

## How to solve Sudoku?

**1. Find the maximum filled squares**

Find the maximally filled squares or square and fill in the missing numbers. In the central square, we can write the number 1, because there is already a 1 in the top square and only one free cell remains. In the remaining cell we write the number 7.

In the bottom square, we can also write the number 1, because there is a blocking 1 in the line. We write down the number 1 and the number 4 in the remaining cell. This square is also filled.

**2. Find squares with blocking lines and pillars.**

The bottom center square has rows and columns with a blocking number 1, so we can easily write it down.

There are also lines and pillars that I block the number 2, we write it down.

So far we cannot write down the number 3, because we do not know in which cell to write it. But for number 4 there are blocking rows and columns. We write it down.

Continuing to search for blocking rows and columns, we solve this square to the end.

Thus, going through the rows and columns, we solve the free Sudoku puzzles to the end.

**Useful Resources**

Sudoku history

**Ways to solve sudoku**