Play Tetris Online: A Step-by-Step Guide

Visit a website that offers online Tetris games, such as 'tetris.com', 'tetrisfriends.com' or 'tetris-games.org'.

Create an account, if necessary. Some websites may require you to log in with an existing account, such as Facebook or Google.

Select the game mode you want to play. Tetris games typically offer different game modes, such as Marathon (play until you lose), Ultra (play as long as you can) and more.

Use the arrow keys on your keyboard to move and rotate the falling blocks. Press the spacebar to drop the blocks faster.

Clear lines by forming horizontal rows with the blocks. The more lines you clear at once, the higher your score will be.

Play until you lose or reach the goal of the game mode you selected.