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	569
Std. Deviate	95
Minimum	60
Maximum	2564

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	2565	2026-01-03
2	60	2026-04-11	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	1060	2011-06-30
6	365	2018-01-17	1030	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	951	2009-11-18
10	374	2013-05-01	942	2010-02-06
11	374	2020-08-09	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	906	2010-12-25
15	379	2025-02-28	898	2010-10-06

Number of People Who Solve a Sudoku

Most Difficult Sudokus

These Sudokus have been solved lest often: