Help - Interactive Sudoku Solver

Overview

The Interactive Sudoku Solver (ISS) is a fast web-based solver for Sudoku puzzles and variants. It prioritizes raw speed over human-style solving techniques to allow exploration of complex solution spaces. Use it to find all the solutions, count the solutions, or see all the valid values for each cell in a puzzle.

Note: The solver runs fastest on Chrome.

Visit the github repository to view the source code and report bugs.

Basic Controls

Select a cell and type a number to set a value.
Drag or Shift+click to select multiple cells. Ctrl+click (or ⌘+click on Mac) to select a rectangle from the current cell to the clicked cell.
+ Segment (below the grid) sets the current selection as a segment and starts a new one, letting you build a selection from several separate segments. Constraints such as Equal Sum apply to each segment separately. By default, constraints will use all the selected cells together, in which case segments can be used to repeat cells. Clear resets.
Select an arrow outside the grid to set outside clues such as Little Killer or Skyscraper constraints.

Keyboard Shortcuts

The following keyboard shortcuts are available:

Grid Navigation & Input

`Arrow keys`	Move selection in the grid
`1` – `9`	Enter a digit in selected cell
`Backspace` / `0`	Clear selected cell
`f`	Fill selected cells with sequential digits (1, 2, 3, ...)

Solving

`Ctrl`+`Shift`+`Enter` / `⌘`+`Shift`+`Enter`	Solve
`n`	Next solution
`p`	Previous solution
`s`	Go to start
`Shift`+`Drag` / `Shift`+`Click`	Extend selection
`Ctrl`+`Drag` / `Ctrl`+`Click` (or `⌘` on Mac)	Select rectangle from current cell to target
`Alt`+`Click`	Pin a value in a cell (Step-by-step mode)

Code Sandbox

`Ctrl`+`	Toggle sandbox panel
`Ctrl`+`Enter` / `⌘`+`Enter`	Run code (when sandbox is open)

History

`Ctrl`+`z` / `⌘`+`z`	Undo
`Ctrl`+`Shift`+`z` / `⌘`+`Shift`+`z`	Redo

Debug

Ctrl+d

Toggle debug panel

Constraint Categories

All Constraints by Category

Recipes

Some constraint types aren't directly supported but can be constructed using combinations of available constraints. These have their own Recipes help page — the available recipes are:

JavaScript Sandbox

The Sandbox API may change without notice.

The Sandbox API exposes internal solver details directly which were not originally designed for general use. There will be rough edges.

The JavaScript Sandbox can be used to create more complex puzzles by writing JavaScript code that programmatically creates constraints.

Open the sandbox from the settings menu in the top-right corner, or by pressing Ctrl+` shortcut.

The sandbox provides access to all constraint types and utility functions for working with cell IDs. You can generate constraints dynamically, parse and modify existing constraints, or create constraints that would be tedious to add manually.

Run help() in the sandbox console to see the full reference, or expand the section below:

Sandbox Help Reference