A puzzle looks wrong
Every board is machine-verified to have exactly one solution reachable by pure deduction, so if one seems impossible or looks like it has two answers, that's worth telling us about. Include the puzzle's date and difficulty (or paste the URL) and we'll check the generator's output against it.
Something is broken
Tell us what you were doing, what happened, and which browser and device you were on. If a board wouldn't load or a solve didn't save, that detail is usually enough to find it.
Reprints, licensing, and syndication
The daily puzzles and the printable books are generated in-house. If you'd like to use them in a newsletter, classroom, magazine, or app, get in touch and say roughly how many puzzles you need and how often.
Feature requests
Suggestions genuinely shape what gets built next — much of what's on the site started as a player's email. There's no promise of a reply to every one, but they all get read.
Accounts and your data
To change or delete your account, or to ask what's stored about you, email the address above from the address you signed up with. What we collect and why is set out in the privacy policy.
More about who makes this and how the puzzles are built is on the about page.