81Sudoku
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Last updated: July 20, 2026
These terms cover your use of 81Sudoku ("81Sudoku", "we", "the site"), a free Sudoku puzzle game at 81sudoku.com. By using the site, you agree to these terms. There's no formal company behind 81Sudoku - it's an independently run, small-scale project - so read "we" and "the site" throughout as referring to 81Sudoku itself.
81Sudoku is an actively developed, independently run project. Features may change, break, or be removed as the site develops, and the game is provided on an "as is" basis without any guarantee that it will always be available or work perfectly. We do our best to keep things running, and error reports are monitored so problems can get fixed, but we can't promise uninterrupted or error-free service.
You don't need an account to play. If you do create one, you're responsible for keeping your password secure and for the activity that happens under your account. You must provide a working email address for account verification and password resets. Don't use someone else's account without permission, and don't try to abuse, disrupt, or overload the site.
Play fair. Don't use the site to send spam, upload malicious content, attempt to bypass its anti-abuse protections, or otherwise misuse the signup, feedback, or account systems for anything other than their intended purpose. We reserve the right to suspend or remove accounts that abuse the service.
If you submit feedback through the feedback form, you're giving us permission to read and use it to improve the site. Feedback submissions aren't made public.
The 81Sudoku name, design, and puzzle-generation/hint system are the property of 81Sudoku. You're welcome to play and share links to the site; please don't copy or republish the site's code, content, or puzzle-generation approach without permission.
81Sudoku is provided free of charge, "as is," with no warranties of any kind, express or implied. As a small independent project, we can't be held liable for any loss or damage arising from your use of the site, including lost game progress, downtime, or bugs. If something goes wrong, please report it via the feedback form or by emailing us - we do actively fix issues that get reported.
Because 81Sudoku is under active development, both the site and these terms may change over time. We'll update the "Last updated" date above whenever these terms change.
Questions about these terms can be sent to [email protected].
See also our Privacy Policy for how we handle your data.