Giant Sudoku grid

25x25 Sudoku

Play a giant 25 by 25 Sudoku grid with 625 cells, twenty-five 5x5 boxes, full-board context, and a focused editor for working through one box at a time.

Try 16x16 first
Cells 625
Boxes 25
Symbols 1-25
Starter puzzle ready.

Whole board

Box 1: rows 1-5, columns 1-5

No cell selected 1

Choose a number for the selected cell

Select a symbol, then tap cells to sketch a giant Sudoku layout.

How 25x25 Sudoku works.

25x25 Sudoku follows the same core rule as classic Sudoku: each symbol appears once in every row, column, and box. The difference is scale. Instead of 9 rows and 3x3 boxes, the grid uses 25 rows and 5x5 boxes.

If 25x25 feels too large, start with 16x16 Hexadoku before moving up to a giant grid.

How to read a 25x25 puzzle

  1. Use symbols 1 through 25, or a letter set if the puzzle provides one.
  2. Scan one 5x5 box at a time so the grid does not become visually noisy.
  3. Track candidates in small groups instead of trying to hold all 25 symbols in memory.
  4. Print the grid when you need more room for pencil marks.

Tips for solving giant Sudoku.

25x25 Sudoku is less about speed and more about control. Keep the whole board visible for context, then use the focused 5x5 editor when you need accurate entries on a phone or tablet.

Work from structure first

  1. Scan the full board for rows, columns, or boxes that already have several clues.
  2. Use the 5x5 box focus to place confirmed values without losing the surrounding board.
  3. Check the puzzle regularly so duplicate numbers do not spread across a large section.
  4. Print a blank grid when you want more room for candidate notes.

9x9 vs 16x16 vs 25x25 Sudoku.

The jump from 16x16 to 25x25 is larger than it looks. A 25x25 board has more than seven times as many cells as a classic 9x9 puzzle, so most of the challenge is organization and visual tracking.

Grid Cells Boxes Best use
9x9 81 9 boxes of 3x3 Daily solving and standard strategy practice.
16x16 256 16 boxes of 4x4 Large-grid practice without the full 25x25 workload.
25x25 625 25 boxes of 5x5 Giant Sudoku, printable challenges, and advanced notation practice.

Large-grid Sudoku resources.

Use this page as the 25x25 hub, then go deeper with Hexadoku and Sudoku variation guides on the Pure Sudoku blog.

25x25 Sudoku FAQ

What is 25x25 Sudoku?

25x25 Sudoku is a giant Sudoku puzzle with 25 rows, 25 columns, and twenty-five 5x5 boxes. Every row, column, and box must contain the full symbol set once.

What symbols does 25x25 Sudoku use?

Most 25x25 Sudoku puzzles use numbers 1 through 25. Some puzzle makers use A through Y, or another 25-symbol set, as long as each symbol is distinct.

Can I play 25x25 Sudoku online here?

Yes. Start the 25x25 puzzle on this page, fill cells with the 1-25 number controls, reset the starter puzzle, check your entries, or print a blank giant Sudoku grid.

Can I print a 25x25 Sudoku grid?

Yes. Use the print control to print the 25x25 board. The printed sheet uses the same 25 rows, 25 columns, and twenty-five 5x5 boxes shown on the page.

Is 25x25 Sudoku harder than 16x16 Sudoku?

Usually, yes. 25x25 Sudoku has 625 cells, while 16x16 Sudoku has 256 cells. The main difficulty is keeping the symbol set and 5x5 boxes organized.