Daily Sudoku
A full 9×9 Sudoku with Notes, logical technique coaching, undo, keyboard navigation and an independently verified unique solution.
More tools & learning
Explain the current position
Reads only the visible board. Named techniques come first; exact contradiction is used only when the named set cannot advance. Opening live analysis marks the current solve Assisted.
Find the logic pattern
Candidate states come from the existing independently verified Sudoku source bank. Drill answers are generated and rechecked by the local human-logic engine.
Technique Academy
Progress from Singles and locked candidates through pairs, triples, X-Wing, Swordfish and Skyscraper. The 40 V0.78 drills stay frozen; 32 advanced drills are derived from the same verified 160-puzzle source bank.
Analyze any Sudoku without uploading it
Paste 81 cells using digits and 0 or . for blanks. The lab checks validity and exact solution count, builds candidates, then walks named human techniques before an explicit exact-contradiction fallback.
Worksheet pack
Print 1, 2 or 4 verified puzzles plus matching answer-key pages. Use your browser’s Print → Save as PDF for a portable worksheet.
Accessibility & local history
Settings and recent solver analyses stay in this browser. No puzzle text is uploaded.