# pgn4web help

pgn4web is a chess games viewer for websites, blogs and live broadcasts.

The user can interact with the chessboard using the keyboard, clicking chessboard squares (hovering the mouse on each square displays an help summary) or using touch gestures.

A search tool allows searching within the PGN games.

Errors alert messages are logged, such as failures to load PGN games, incorrect PGN games or incorrect FEN strings. When an error is encountered, a chessboard square will flash to signal the exception. The error alert log can be reviewed clicking on the flashing chessboard square.

See the pgn4web wiki for more information. Please note, the wiki information always refers to the latest version of pgn4web.
The user can interact with the chessboard using the keyboard. See the pgn4web wiki for more information. Most commonly used shortcut keys:
The user can interact with the chessboard clicking chessboard squares:

Access the search tool either directly with the search form (if available on the web page) or via the popup search box invoked with the 's' shortcut key and/or the associated shortcut squares.

For full details about the search tool (implemented as regular expression match of the text of the PGN game), please refer to the pgn4web wiki; please find below a sample list of useful search patterns:

Chess annotations symbols as defined by the Chess Informant publishing company:
Javascript modifications of Paolo Casaschi on code from the ficsgames database, in turn likely based on code from the LT PGN viewer.

PNG images from Eric De Mund, licensed under creative commons attribution 4.0 international license.
SVG images from Colin M.L. Burnett, licensed under GFDL, CC-BY-SA-3.0 or GPL, via Wikimedia Commons.
SVG images from Igor Krizanovskij and other SVG images, dedicated to the Public Domain as any openclipart.org content.

The figurine fonts are derived from the Liberation Sans font released under GNU General Public License, with the addition of chess pieces from freeware fonts: the alpha2 font (Peter Strickland), the good companion font (David L. Brown), the merida font (Armando H. Marroquin), the pirate font (Klaus Wolf) and the chess usual font (Armando H. Marroquin). The original chess fonts and more details are available at the en passant site. The chess informant symbols font is used with permission from the Chess Informant publishing company. The chess ole figurin font is from the ChessOLE project (David Frank) and is available at the en passant site.

The GarboChess javascript chess engine is licensed by Gary Linscott under BSD license.

Some functionality of specific applications of pgn4web or specific demo pages depends on third party javascript libraries, each stored in a separate subfolder with the associated credits and license information.

Remaining pgn4web code is copyright (C) 2009-2026 Paolo Casaschi and licensed under the terms of the GNU General Public License version 2 as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.