Crossword Grid Helper

Summary

Build a crossword grid up to 21x21, toggle black squares, and get automatic cell numbering in the standard crossword format.

How it works

1. Set the number of rows and columns using the controls (3 to 21 each).
2. Click any white cell to make it a black square; click a black square to restore it to white.
3. Cell numbers update instantly whenever you change the grid, following standard crossword rules.
4. Use the Symmetry toggle to automatically mirror your black squares across the center.
5. Click Clear to reset all black squares, or Export to download the grid layout as a text file.

Use cases

• Draft a crossword puzzle layout before writing clues.
• Check whether a grid design produces a valid numbering pattern.
• Generate symmetric crossword grids quickly with the symmetry toggle.
• Experiment with different grid sizes from mini 5x5 to full 21x21.
• Share a grid pattern by exporting the text representation.
• Teach students how standard crossword numbering works.

Frequently Asked Questions