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

What does “Sudocle” mean?

The name Sudoko 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!

Posted by Michel Krämer
on March, 7th 2021.