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Alphadoku - 25x25 sudoku puzzles to play online

60,000 25x25 sudoku grids to choose from

A variant of Sudoku is the alphadoku puzzle comprised of 25 squares by 25 squares. In this type of puzzle the letters A to Y of the alphabet are used.

There are 60000 grids to choose from. There are two types of puzzles with three skill levels for each grid type.
 Grid Types: Asymmetrical or Symmetrical.
 Skill Levels: Beginner, confirmed and expert.

There is only one solution possible per puzzle. Using one’s logic in a sequential fashion is all that is needed to solve the puzzle. Neither hypothetical theories nor multiple choices are needed to find the solution.

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Choose a random puzzle:  
Level:    OK button.
Forms: Symmetric     Asymmetric

Select a puzzle: 
Level:    OK button.
        (From 1 to 10,000)
Forms: Symmetric     Asymmetric

 Saving a game 

25x25 puzzles are long to resolve.
You can save games in progress and reload them later.

 Google Chrome Browser 

We suggest using Google Chrome. Indeed its execution speed is very valuable in the display of the 625 cells of this type of grid and the online help.


Choosing alphadoku puzzles: These puzzles have been produced and ranked in such a manner so that the higher the puzzle number of a specific level, the more difficult the solution is. When solving either the symmetrical or asymmetrical alphadokus, the difficulty is roughly equivalent between the corresponding puzzle numbers of the two types within a certain skill level. The symmetrical puzzles are slightly easier to solve. The fact that symmetrical puzzles are, in fact, symmetrical they already have an extra constraint and thus there are fewer empty squares. Please note that the degree of puzzle difficulty can vary from person to person. Difficulty is a subjective concept and each player solves puzzles different ways using different methods with which he or she feels at ease.

Alphadoku puzzles: These puzzles are a variation to standard Sudoku puzzles. They enable seasoned players to find additional difficulty. The alphadoku 25X 25 square puzzles also serve as practice for experienced competitors and the habitual fans of the original Sudoku 9X9 puzzle.

 Playing by skill level 

• "Beginner" level puzzles can be solved using the "Inclusion" methods while acknowledging other existing methods.
• "Confirmeded" level puzzles are solvable using both the "Inclusion" and "Exclusion" methods while acknowledging other existing methods.
• "Expert" level puzzles are solvable by using "Inclusion", "Exclusion" and "Pairs exclusive" methods.
Refer to How to solve for further information regarding these three solution methods, identical to those used for Sudoku 9X9 puzzles.

 Symmetric and Asymmetric Alphadoku puzzles 

Like Sudoku puzzles, alphadoku puzzles are symmetrical when the squares of which they are composed are equally arranged around the central square. The central square is also considered the center of symmetry and has only an esthetic value. Nothing is changed as far as what method is used for solving the puzzle. On the other hand, the benefit of non-symmetrical puzzles is that they allow for increased puzzle complexity with more difficulty since they have one less constraint.

 Downloading and Printing 

Our alphadoku puzzles are downloadable and printable through the menu 25X25 SUDOKU and the link Download pdf and Print puzzles.

 Free reproduction 

All these Alphadoku - 25 x 25 puzzles - of this site are created by and these puzzles can be reproduced free on condition that a link to appears on every reproduced page.

Play a alphadoku grid.