About Sudoku Luna
Sudoku Luna is a sudoku site with no registration wall, no app download and no paywall. This page explains who runs it and how it works.
What this site offers
Classic sudoku in four difficulty levels, Killer Sudoku, a daily challenge, a solver that explains each step, a learning path covering 36 techniques, printable sheets and a section for children. Everything runs in the browser, in seven languages.
Where the puzzles come from
Every puzzle is generated on our own servers and checked for a unique solution before it is handed out. The difficulty label comes from which techniques a solution actually requires, not from how many cells are empty — that is why a grid with few givens can still be easy.
Why it is free
Advertising pays for hosting and development. That is also why the site asks about cookies: without consent we show no personalised advertising, and the game remains fully usable.
Do I need an account?
No. Playing, printing and learning work without one. An account only becomes useful if you want your statistics, streak, badges and learning progress to follow you across devices, or if you want to duel friends.
Who runs this site
Sudoku Luna is operated by a Swiss web agency. Full details are in the imprint. Imprint
Questions or feedback
Write to us — a mistake in a puzzle, a wrong translation or a feature you are missing are all worth a message. Contact · info@sudoku-luna.com