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

Average	570
Std. Deviate	92
Minimum	60
Maximum	1699

Easiest and Hardest Sudokus

The Sudokus that were solved fastest/slowest on average.

	Easiest		Hardest
No	Mean Time [s]	Sudoku	Mean Time [s]	Sudoku
1	60	2006-06-05	1699	2011-01-22
2	60	2025-05-21	1215	2013-07-09
3	355	2019-08-09	1083	2006-10-14
4	355	2017-06-09	1063	2011-06-30
5	362	2015-06-29	1035	2010-04-21
6	369	2019-03-13	973	2008-10-29
7	369	2020-07-10	967	2022-01-28
8	370	2018-01-17	954	2009-11-18
9	370	2013-05-02	945	2010-02-06
10	371	2020-08-09	941	2013-03-06
11	373	2013-05-03	921	2012-02-04
12	376	2013-05-01	915	2013-08-21
13	377	2007-06-16	914	2010-12-25
14	377	2019-09-27	894	2009-08-08
15	379	2017-10-13	894	2010-10-06

Number of People Who Solve a Sudoku

Most Difficult Sudokus

These Sudokus have been solved lest often: