Constructor's Guide
Build publication-quality 15×15 and 21×21 crosswords — from theme design to submission.
Pro features at a glance
15×15 and 21×21 grids
Standard daily and Sunday sizes, plus any custom odd size up to 25×25.
AI-assisted autofill
AC-3 + MRV/LCV solver against a 200K+ scored word list.
Rebus cells
Multi-letter cells with full .puz GRBS/RTBL export.
Cell coloring & patterns
12-color palette, diagonal stripes, dots. Preserved in .jpz, .ipuz, PDF, and HTML.
Publication checklists
NYT, LAT, Universal, WSJ per-item checklists with fix shortcuts.
Floating toolbar
Six specialized tools: Select, Rebus, Black Cell, Shape, Paint, Eraser.
AI clue generation
Multi-provider BYOK (Anthropic, OpenAI, Gemini, Groq, and more).
.puz / .jpz / .ipuz export
Full binary-correct .puz with checksums. Plus PDF, HTML player, and PNG.
Construction workflow
Start with the theme and work backwards. Place your longest theme entries first, then build the grid around them. Use 180° rotational symmetry — the NYT standard.
- • Theme entries typically go at 1-Across, mid-Across, and the last long Across.
- • Aim for 15–18% black squares on a 15×15. Above 20% feels choppy.
- • Stacked long entries are impressive but constrained — every crossing must be valid.
- • Random Grid (Grid tab → Generate) gives you a valid starting pattern to modify.
- • The New Puzzle wizard also offers a library of preset black-square patterns to start from.
Right-click any cell for fast black square placement, rebus entry, and cell coloring.
Key keyboard shortcuts
External resources
Square One handles the technical side. For the craft of construction, these resources are invaluable:
- •NYT Crossword submission guidelines
- •Los Angeles Times submission guidelines
- •XWord Info — Searchable database of NYT crosswords and clue history
- •Cruciverb — Constructor community forum and word list resources
- •r/crossword on Reddit — Feedback and community