Chess server

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The transmission of the 5th game of the 2008 World Chess Championship by the FICS chess server

A chess server ( Internet chess server ) enables chess to be played with remote opponents over the Internet. Technically speaking, chess servers are a subset of game servers . Sometimes you can play directly in the web browser , sometimes you have to install your own access software.

There is a large number of free and commercial chess servers, which differ greatly in their functionality and operation. A basic distinction must be made between “live chess” and correspondence chess . In the first case, both players are online at the same time and play against each other in real time. In correspondence chess, the thinking time is so long that the players only register to make one move at a time. Correspondence chess does not in and of itself require the support of chess servers and, before its invention, was played simply by sending postcards. However, the possibilities of the Internet make it much easier.

Many chess servers offer both forms of chess.

When the Covid-19 pandemic broke out , chess servers received a large number of visitors. Many clubs have recommended their members to continue playing against each other online. The Magnus Carlsen Invitational was organized as the first world class tournament . Other tournaments, also in cooperation with FIDE , were held online or are planned.

Live chess

In live chess, both opponents remain logged on to the chess server throughout the game. You can choose between different thinking time regulations and sometimes also chess variants . Many chess servers offer so-called 1-click entries of moves, with which moves can be made very quickly. In addition, so-called “pre-moves” can be set as response moves to any opponent move, for example repelling in an exchange . This enables very short thinking times (one minute per game), which are known as bullets and which are hardly feasible on the chessboard without computer support. Due to the constant availability of opponents, chess servers have partly led to a popularization of rare chess variants, such as B. Insert chess or tandem chess . Chess programs can also be played against each other on chess servers . Some chess program authors use chess servers to test their program against human opponents and other programs.

An important difference to real chess (in English often "OTB" = "over the board") concerns illegal moves. The chess server software does not allow illegal moves. This means that it is absolutely impossible for a player to make an illegal move. In real Blitz games, however, an illegal move is punished with a time premium the first time and the loss of the game the second time, provided the opponent has complained.

A big problem with chess servers is fraud through computer support during the games. Some chess servers have therefore developed algorithms with which they examine the games for computer support. The functioning of these algorithms is controversial and secret, but at least the commercial chess server operators take rigorous action against fraudsters in order to counter complaints from users.

Correspondence chess

A correspondence chess server enables games to be played with very long thinking times (several days per move), in which the opponents only register for the move and then log off again. On a remote chess server, the moves are made on a clickable board on a website and, after a preview, the move is confirmed. This changes the right to move and the opponent's time begins to run. The opponent is informed of the move by email. Often it is possible to enter “contingency moves”, which are automatically executed if the opponent makes a certain anticipated move.

Correspondence chess servers have grown in popularity among correspondence chess players in recent years. The transmission of the moves in correspondence chess always posed a technical and organizational challenge. In addition to long mail delivery times, there were also misunderstandings and errors in the transmission, as well as disputes about the time used to think about it. With remote chess servers, on the one hand, it is possible to transmit the moves without loss of time, and on the other hand, the course of the game and the reflection time are managed on the server so that there can be no misunderstandings about the course of the game. Most correspondence chess servers also offer move validation and administration of vacation times in a tournament.

More features of chess servers


Almost all chess servers calculate values ​​for their users that work similarly to the Elo system in real chess. This makes it possible for every user to estimate the skill level of other players to some extent. However, the comparability of online numbers to real Elo numbers is rather questionable.

Analysis board

In correspondence chess in particular, it is possible to play through variants in advance on the screen and to save them conveniently.

Opening and game databases

Often the users of chess servers have access to extensive databases. On the one hand, this can be used for self-study, on the other hand, such a database is an important tool that is absolutely legal in correspondence chess games (but not in live chess games!).


Many chess servers offer access to powerful chess programs for analyzing a completed game, for following a master’s game, for training or for evaluating positions . These often also enable automatic game analysis.


The offer of most commercial chess servers is extended by an extensive additional offer. Depending on the chess server, it can be about training units, chess problems , reports on championship tournaments (sometimes live), texts and videos about chess, chat rooms , forums, etc. Many commercial chess servers offer different memberships. The membership fee is then mostly based on the scope of the additional features that can be used, while the mere playing of live games is often free of charge.

Well-known chess servers

Free chess servers

Commercial servers

Web links