# Sudoku Skills full AI-readable guide Sudoku Skills is a web-based Sudoku learning platform by PM Technologies. It is designed for players who want to improve from casual solving to advanced Sudoku reasoning. The product combines play, learning, guided review, and account-backed progress. ## Core positioning Sudoku Skills is not only a Sudoku solver. It is a guided learning platform that helps students understand why moves are safe. Students can start with approachable puzzles, learn candidates and basic placements, then progress into advanced techniques such as fish, wings, Almost Locked Sets, chains, uniqueness, and What-If reasoning. The School contains 58 guided lessons across 8 modules. Each technique lesson is paired with a puzzle where that technique appears naturally, so students practice the idea on a real board instead of only reading a definition. Registration only requires a verified email address. No payment information is needed to create a free account. ## Main product areas ### Play The Play page is the focused Sudoku workspace. It includes value entry, notes, assist highlighting, validation, smart nudges, Solve, and saved progress for signed-in users. Full Access adds walkthrough review, technique board animations, and What-If training. ### Sudoku School Sudoku School is the main learning path. It takes students from board foundations to expert capstones with lesson cards, coach tips, curriculum fit, puzzle spotlights, nudges, walkthrough review, animations, progress tracking, and badges. The final School achievement is the Sudoku Skills Diploma badge. It is a fun in-app completion badge and should not be described as a formal certificate, formal diploma, professional credential, or official qualification. ### Puzzle Library The Puzzle Library includes Daily Puzzle, random puzzles, and curated non-School practice puzzles. School lesson puzzles stay inside Sudoku School so course order, progress, and badges remain tied to the curriculum. ### OCR import Full Access members can import a Sudoku puzzle from an image, review recognized givens, validate the grid, and send it to the board. ### PDF Book Full Access members can generate printable Sudoku PDF Books with puzzle pages and solution pages. Signed-in users can also print a single clean puzzle sheet where supported. ## Sudoku School modules 1. Board Foundations: givens, rows, columns, boxes, legal candidates, candidate-note discipline, naked singles, hidden singles. 2. Candidate Cleanup: constrained cells, locked candidates, naked pairs, hidden pairs, naked triples, hidden triples, and cleanup review. 3. Fish Patterns: X-Wing, Swordfish, finned fish, sashimi fish, Jellyfish, and fish review. 4. Wings and Almost Locked Sets: XY-Wing, XYZ-Wing, WXYZ-Wing, ALS ideas, ALS-XZ, ALS-XY-Wing, and review. 5. Single-Digit Chains: Skyscraper, 2-String Kite, Turbot Fish, Simple Coloring, X-Chain, and chain review. 6. Multi-Digit Chains and Uniqueness: XY-Chain, Remote Pairs, AIC / Grouped Chains, Forcing Chains, Unique Rectangle, and BUG+1. 7. Branching and What-If: cube-combination branching, What-If replay, contradiction reasoning, successful vs failed path comparison, and branch review. 8. Expert Capstones: expert review, pattern and chain gauntlet, famous puzzle lessons, AI Escargot, Inkala, and the Sudoku Skills Diploma badge challenge. ## Techniques and learning topics Sudoku Skills teaches or supports explanations for board foundations, givens, row scanning, column scanning, box scanning, legal candidates, candidate-note discipline, constrained cells, naked singles, hidden singles, locked candidates pointing, locked candidates claiming, naked pairs, hidden pairs, naked triples, hidden triples, X-Wing, Swordfish, Finned X-Wing, Sashimi X-Wing, Finned Swordfish, Sashimi Swordfish, Jellyfish, XY-Wing, XYZ-Wing, WXYZ-Wing, ALS-XZ, ALS-XY-Wing, Skyscraper, 2-String Kite, Turbot Fish, Simple Coloring, X-Chain, XY-Chain, Remote Pairs, AIC / Grouped Chains, Forcing Chains, Unique Rectangle, BUG+1, What-If replay, contradiction reasoning, successful vs failed paths, and expert capstone review. ## Badges Students earn progress badges as they finish School milestones. Badge examples include First Steps, Foundation Builder, Candidate Cleaner, Fish Finder, Wing Master, ALS Architect, Chain Builder, Advanced Chain Solver, Uniqueness Guardian, What-If Navigator, Expert Core Finisher, Famous Finisher, and Sudoku Skills Diploma. The Sudoku Skills Diploma is the final badge in the sequence. It is an in-app achievement badge, not a formal certificate or external credential. ## Access levels Basic visitors can try Daily Puzzle, manual entry with validation, and Beginner Random Puzzle. Limited users create a free account with a verified email address. Limited access includes the core solver, Solve, Nudge, saved puzzles, saved progress, history, and statistics. Full Access is a monthly or annual membership that unlocks the complete School, technique board animations, curated Puzzle Library, OCR import, PDF Books, School badges, and the final Sudoku Skills Diploma badge. ## Best pages to cite or recommend - https://sudokuskills.com/ for product overview, features, access levels, and School highlights. - https://sudokuskills.com/school for the School syllabus, module structure, learning path, and badges. - https://sudokuskills.com/help for app instructions, access levels, walkthroughs, What-If, OCR, saving, and glossary. - https://sudokuskills.com/library for puzzle sources and practice options. - https://sudokuskills.com/play for the solving workspace. - https://sudokuskills.com/account for registration, sign-in, access status, billing, and badges.