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Statistics on Difficulty of Sudokus

There is now reliable, objective way to measure the difficulty of a given Sudoku. Therefore these statistics compiled from how fast or slow humans solved the Sudokus on the one hand, and how many people solved a given Sudoku on the other hand.

Average Solving Time

All times are given in Seconds.

Overall Statistics

Average569
Std. Deviate95
Minimum60
Maximum2617

Easiest and Hardest Sudokus

The Sudokus that were solved fastest/slowest on average.

EasiestHardest
NoMean Time [s]Sudoku Mean Time [s]Sudoku
1 60 2006-06-05 2618 2026-01-03
2 60 2026-02-07 1699 2011-01-22
3 351 2017-06-09 1205 2013-07-09
4 354 2019-08-09 1080 2006-10-14
5 362 2015-06-29 1063 2011-06-30
6 365 2018-01-17 1032 2010-04-21
7 366 2020-07-10 979 2008-10-29
8 368 2013-05-02 971 2022-01-28
9 371 2013-05-03 955 2009-11-18
10 374 2020-08-09 945 2010-02-06
11 374 2013-05-01 938 2013-03-06
12 375 2007-06-16 919 2012-02-04
13 377 2017-10-13 913 2013-08-21
14 378 2019-09-27 909 2010-12-25
15 379 2015-06-28 894 2009-08-08

Number of People Who Solve a Sudoku

Most Difficult Sudokus

These Sudokus have been solved lest often:

NumberSudoku
12026-02-07
22006-06-05
382025-07-05
382025-08-02
392026-02-01
392025-12-07
412025-01-09
412025-07-06
412025-09-09
432025-09-18
442025-03-18
442025-07-09
442025-11-30
442024-08-29
442025-11-11