Sudocle: A modern web app for Sudoku

I’m a huge Sudoku fan. Today, I’m releasing the first version of my new web app called Sudocle. The app has been inspired by Cracking the Cryptic, the world’s most popular YouTube channel about Sudoku and other logic puzzles, which I can highly recommend!

Sudocle offers the following features:

  • Lightweight and clean look
  • Optimised for various devices (mobile and desktop) as well as screens (any size and resolution)
  • Configurable interface:
    • Themes (including dark mode)
    • Colour palettes (including one optimised for colour blindness)
    • Custom colour palette
    • Zoom
    • Font sizes
    • and other options
  • Fully compatible with puzzles published by Cracking the Cryptic (see usage instructions below)
  • High performance graphics renderer using WebGL or HTML Canvas
  • Open-source (MIT license)

Using the online version

If you want to try Sudocle, I recommend using the online version, which is available at:

To play one of the puzzles featured on Cracking the Cryptic in Sudocle, just copy the puzzle’s ID from the CTC webapp and append it to the URL shown above.

For example, the “Miracle Sudoku” by Mitchell Lee, one of the most popular puzzles ever featured on the channel, has the following URL:

This URL becomes:


Here are some random screenshots (no spoilers!):

The Gordian Knot
by Joseph Nehme
Play in Sudocle
Watch video with rules

German Whispers
by Philipp Blume
Play in Sudocle
Watch video with rules

by apiyo
Play in Sudocle
Watch video with rules

Chaotic Wrogn
by Undar Beyond
Play in Sudocle
Watch video with rules

What does “Sudocle” mean?

The name Sudoku is an abbreviation of the Japanese expression “Sūji wa dokushin ni kagiru” (数字は独身に限る), which can be translated to “the digits must be single” [Wikipedia]. Sūji means digits.

A monocle, a binocle, or a pair of binoculars are things that help people see.

Sudocle therefore helps people see digits 🤓😉

Have fun!

If you have used Sudocle and have ideas, found bugs, or have any other feedback, I would be very happy to hear from you! Contact me, write a comment below, or open an issue.

You can find Sudocle’s source code on GitHub. Contributions are welcome!

Have fun solving puzzles with Sudocle!

Profile image of Michel Krämer

Posted by Michel Krämer
on 7 March 2021

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