Masu Puzzle is a free puzzle site run by an independent developer. We collect as little as we can: no accounts, no ads, and nothing is sold.
Kept in your browser only
Your puzzles in progress, solve times, streaks, statistics and settings are saved in your browser’s local storage. They aren’t sent to us. Clearing this site’s data in your browser deletes them, and they don’t follow you to another device.
Your browser also keeps a random ID (letters and numbers, not linked to your name, email or device) so the same solve isn’t counted twice. It’s sent with the things described below.
Sent to our server
- Daily solve times. When you finish a daily puzzle, its number, your time and your random ID are recorded so we can show how your time compares and build the daily leaderboard.
- Your leaderboard name. If you choose one, it appears publicly next to your daily times. Use a nickname rather than your full name. You can change it any time on Your statistics.
- Challenges. When you make or join a challenge, the name you type and your time are shown to anyone who has that challenge’s link.
- Email sign-ups. If you ask to hear when a new puzzle launches, we store your email address, which list you joined and the page you were on. We only use it to tell you about Masu Puzzle. Every email will say how to stop them.
- Feedback. Messages you send through the feedback form, and your email address if you add one so we can reply.
Usage statistics
To see which puzzles people enjoy and where they get stuck, the site notes events like starting, finishing or leaving a puzzle, opening a lesson, or sharing a result. These include the puzzle, its size and how long it took, but not your name, email or board.
We count visits and the events above with PostHog, on its US servers. Along with each event it records the page, the site that linked you here, your browser and device type, and an approximate location (country and city) worked out from your IP address. It’s set up to use no cookies and to store nothing in your browser; return visits are recognised by the random ID described above. PostHog processes this for us and doesn’t use it for advertising.
Who handles the data
The site is hosted by Vercel, the server data above is stored with Supabase, and usage statistics are handled by PostHog, all in the United States. Like any web host, they process your IP address and browser details to deliver pages and keep the service secure. They act on our behalf and don’t use your data for their own purposes. We don’t sell or rent personal information, share it for advertising, or show ads.
We may disclose information if the law requires it.
How long we keep it
Solve times, leaderboard names and challenges stay while the site runs, because they make up the leaderboards and challenge boards. Email sign-ups stay until you unsubscribe or ask us to delete them. Feedback is kept as long as it’s useful for fixing and improving the site.
Your choices and rights
You can ask to see, correct or delete what we hold about you, or to stop emails. The easiest way is the feedback form with “Privacy request” chosen: it includes your browser’s random ID, so we can find your solve times and name. You can also email sycognetta@gmail.com. We’ll respond within 30 days.
Depending on where you live (for example the EU, UK or California), you may have further rights, including to object to how we use your data or to complain to your data protection authority. We use your data to run the features you choose to use, and for our legitimate interest in keeping the site working and improving it.
Children
Masu Puzzle is for a general audience and isn’t aimed at children under 13. We don’t knowingly collect personal information from them. If you think a child has given us their email address or real name, send a privacy request and we’ll delete it.
Changes
If we change this policy, we’ll update it here and change the date at the top. See also our terms of use.
Contact
Questions about this policy or your data: sycognetta@gmail.com.