This project implements the Sudoku web app used on SudokuExchange.com.

Features include:

• Enter a puzzle into a blank grid (e.g: transcribe a printed puzzle)
• Check that the puzzle has a unique solution (in case you made a typo)
• Share a puzzle as a link like this
• Two types of pencilmarks (for Snyder notation and doubles/triples or simple candidate lists)
• Cell colouring
• An optional dark mode theme
• Keyboard shortcuts for desktop browsers (including Ctrl-Z/Y Undo/Redo)
• Touchscreen support for mobile or tablet browsers
• Help option on the menu to access user guide
• Multi-cell selections for entering pencil marks
• Flexible display: scales up to huge screens or down to small screens, adapts automatically to portrait vs landscape orientation, and supports full screen mode to remove distractions
• Configurable options so you can turn on the features you find helpful and turn off the features you find annoying
• Free to use and no ads
• Full source code available

Copyright and License

This software is copyright (c) 2019 Grant McLean grant@mclean.net.nz and is released as free software under the terms of the GNU Affero General Public License (AGPL) version 3 or later. You may use, copy, modify and share the software under the terms of that license.