Frequently asked questions
What can I enter as my sequence?
Anything up to 40 characters — digits, letters, or a mix. Spaces are ignored. Examples: an anniversary date like 20260520, a name like EMMA, or a phrase like ILOVEYOU.
Why does my puzzle only use 9 symbols?
Sudoku requires exactly 9 unique symbols. CipherHeart takes the first 9 unique characters from your sequence. If your sequence has fewer than 9, the app fills the rest automatically. You can also click any symbol on the symbol review screen to change it.
What is the path shape?
The path is the highlighted route on the 9×9 grid where your sequence is placed. Different path shapes give your puzzle a different visual pattern. The app tries all rotations of the path automatically to find one that produces a valid Sudoku.
What if no valid puzzle can be generated?
Some combinations of sequence and path shape are very constrained. If the generator can't find a valid arrangement, try a different path shape or direction, or try a slightly different sequence.
Can I share my puzzle with someone?
Yes — use the Share Image button to save the puzzle as an image, or Share Link to copy a URL that recreates your exact puzzle for anyone who opens it.
Can I print the puzzle?
Yes. Use the print button on either the solution or puzzle screen. The interface controls are hidden automatically in print view.
Is CipherHeart free?
Yes, completely free. No account, no login, and no personal information required.
Is my data stored?
No. Everything runs in your browser. Your sequence and puzzle are never sent to or stored on any server. See our Privacy Policy for full details.
Something isn't working — what should I do?
Try refreshing the page. If the problem persists, please contact us and describe what you were doing — we'll look into it.