Data protection policy

Personal data

You can use this website without any personal data if you don't register.
If you register, you have to enter your email address. does not send you unsolicited email, or share your email address with a 3rd party.
We will send you security-related emails, including:
After registering, you get a confirmation email to confirm your email adress.
If you forget your password, and have a confirmed email adress, you can reset your password with a password reset email.
You can also opt-in to receive the newsletter. In that case you will also receive an email with the newsletter.
We also ask for a name. You can enter your real name or an alias or fantasy username.
If you decide to enter your real name you are giving consent to us storing it.
The name you enter is shown to you in the menu as a link to your user settings.
Your name and email address are not shared with anybody else. You can also opt-in to join the leaderboard.
In that case, your name and results will be shown on the leaderboard.


This website is using cookies for technical reasons, including session cookies. An authentication cookie is used to identify registered users who are logged in.
Third party vendors, including Google, use cookies to serve ads based on a user’s previous visits to this website or other websites.

Non-personal data

We are keeping track of which puzzles you have already solved to ensure you don't see the same puzzle more than once.
This includes the ID of the puzzle, date and time of the solving, and if you selected the puzzle as a favorite.
Registered users can see a list of the last solved puzzles and their favorites.
We are also calculating a rating for you, to ensure that you get puzzles with a difficulty corresponding to your puzzle solving level.
If you are logged in, this information is stored in our database.
If you are not logged in, this information is kept in the session, and will be lost when you leave the website.

Server log

To keep track of general usage of the website, and to help finding errors, the host can store data automatically sent by your browser in the server log.
This data includes the browser type and version, operating system used, referrer URL, IP address, and date and time of the request.

Google Analytics

This site uses Google Analytics to track usage of the website.
The IP addresses are anonymized to remove any relation to specific persons.
If you prefer that no data is sent to Google from your browser, you can deactivate it with this tool from Google.

Your rights in connection with your personal data

Under certain circumstances, by law you have the right to:

  • Request access to your personal information (commonly known as a "data subject access request"). This enables you to receive a copy of the personal information we hold about you and to check that we are lawfully processing it.
  • Request correction of the personal information that we hold about you. This enables you to have any incomplete or inaccurate information we hold about you corrected.
  • Request erasure of your personal information. This enables you to ask us to delete or remove personal information where there is no good reason for us continuing to process it. You also have the right to ask us to delete or remove your personal information where you have exercised your right to object to processing.
  • Object to processing of your personal information where we are relying on a legitimate interest (or those of a third party) and there is something about your particular situation which makes you want to object to processing on this ground. You also have the right to object where we are processing your personal information for direct marketing purposes.
  • Request the restriction of processing of your personal information. This enables you to ask us to suspend the processing of personal information about you, for example if you want us to establish its accuracy or the reason for processing it.
  • Request the transfer of your personal information to another party.
If you want to review, verify, correct or request erasure of your personal information, object to the processing of your personal data, or request that we transfer a copy of your personal information to another party, please contact me.