Privacy Policy

Data Collection Practices

We collect data in three ways: information you provide directly, information generated by your use of the game, and information collected automatically by our infrastructure and third-party partners.

Information you provide

• ▸Nickname. A display name you choose freely when you first play. It appears on the public leaderboard. We do not require or link a nickname to any email address, phone number, or real name.
• ▸Recovery code. A 6-character code you may optionally generate. It is stored in our database alongside your nickname to allow account restoration on a new device. Generation is optional; you can play indefinitely without one.

Information generated by gameplay

• ▸Puzzle scores. Your solve time, trophy tier, difficulty level, and puzzle date for each completed puzzle. This is stored in our database and used to power the leaderboard, streak counter, and points total.
• ▸Identity token. A randomly generated UUID created in your browser the first time you play. It is used to prove ownership of your nickname when submitting scores, without requiring a password. It is stored in localStorage and transmitted only to our own API.

Information stored only on your device

The following data lives exclusively in your browser's localStorage and is never transmitted to our servers:

Information collected automatically by infrastructure

• ▸Server request logs. Our hosting provider (Vercel) automatically logs your IP address, browser user-agent, the URL you requested, and the timestamp of each request. These logs are used for security and diagnostics and are retained for up to 30 days by Vercel. We do not process or store these logs ourselves.

Use of Cookies

We do not set any first-party cookies. Shikaku Daily uses browser localStorage (not cookies) for all game-state and preference storage. Unlike cookies, localStorage data is never automatically sent to any server with every request — it stays on your device until you clear it.

However, third-party cookies may be set by our advertising and analytics partners when those services are active. These are described in the sections below. Third-party cookies are governed by those companies' own privacy policies, not ours.

How to manage cookies

You can view and delete cookies through your browser settings. You can also clear Shikaku Daily's localStorage data at any time via your browser's developer tools (Application → Local Storage → shikakudaily.com → Clear All). Note: clearing your identity token means you will need your recovery code to reclaim your nickname and scores.

Google Advertising

Shikaku Daily may display advertisements served by Google AdSense, a service provided by Google LLC. When Google AdSense is active on the site:

• ▸Google may set advertising cookies (such as __gads, IDE, and ANID) on your device to serve ads that are relevant to you based on your browsing history across sites.
• ▸Google collects data including your IP address, browser type, cookie identifiers, and interactions with ad units (impressions and clicks). This data is processed by Google under their own privacy policy.
• ▸We receive aggregated, anonymised reporting from Google (e.g. total impressions and revenue). We do not receive any individually identifiable data about visitors from Google's ad systems.
• ▸Google uses the DoubleClick cookie and similar technologies to help measure the effectiveness of ads and to deliver ads that may be relevant based on prior visits to this and other websites.

Opting out of personalised advertising

You can opt out of personalised ads from Google at any time:

• ▸Visit Google Ad Settings to manage your preferences.
• ▸Use the NAI opt-out tool or DAA opt-out tool to opt out from multiple ad networks at once.
• ▸Install the Google Analytics Opt-out Browser Add-on to block data collection by Google services across all sites.

Opting out means you may still see ads, but they will not be personalised to your interests. For more information, see the Google Advertising Policies and Google Privacy Policy.

Analytics

We do not currently use any analytics service. No Google Analytics, no Mixpanel, no tracking pixels — nothing that monitors how you navigate the site beyond what our hosting provider logs automatically (see Data Collection Practices).

If we introduce an analytics service in the future, this policy will be updated before that service goes live. We will describe exactly what is collected, why, and how long it is retained. Any analytics we adopt will be configured to anonymise IP addresses, disable cross-site tracking, and minimise the data collected to only what is necessary to understand aggregate usage patterns (e.g. which difficulty is most popular, average solve times by difficulty, overall daily active users).

We will never use analytics data to build individual user profiles, serve targeted ads, or share individual-level behavioural data with third parties.

How We Use Your Information

• ▸To display your nickname and scores on the public leaderboard.
• ▸To calculate your streak, points total, and trophy history.
• ▸To authenticate score submissions and prevent leaderboard manipulation.
• ▸To allow you to restore your account on a new device using a recovery code.
• ▸To maintain the integrity and fairness of the daily competition.

We do not sell, rent, or share your personal data with third parties for marketing purposes, and we do not use your data for automated profiling or individual decision-making.

Data Storage and Security

Puzzle scores, nicknames, and recovery codes are stored in Supabase (a managed PostgreSQL service). Data is hosted in the EU (Frankfurt) region. Supabase is GDPR-compliant. All data in transit is encrypted via TLS 1.2+. Data at rest is encrypted by the hosting provider.

We retain your score data indefinitely to maintain leaderboard history. If you would like your data deleted, please contact us (details below) and we will remove your nickname, scores, and recovery code within 30 days.

Third-Party Services

• ▸Supabase — database and API hosting. Processes: nickname, identity token, recovery code, puzzle scores. Privacy policy ↗
• ▸Vercel — web hosting and CDN. Processes: server request logs (IP, user-agent, URL, timestamp), retained up to 30 days. Privacy policy ↗
• ▸Google AdSense (when active) — advertising platform. May set cookies and collect browsing data for ad personalisation. Privacy policy ↗

Children's Privacy

Shikaku Daily is not directed at children under 13. We do not knowingly collect personal information from children under 13. If you believe a child has submitted data through our Service, please contact us and we will delete it promptly.

Your Rights

Depending on your location you may have the following rights regarding your data:

• ▸Access — request a copy of the data we hold about you.
• ▸Correction — ask us to correct inaccurate data (e.g. your nickname).
• ▸Deletion — request that your account and scores be permanently deleted.
• ▸Portability — request your score data in a machine-readable format.
• ▸Objection — object to the processing of your data in certain circumstances.

To exercise any of these rights, please email ••••@•••••••••••• with your request. We will respond within 30 days.

Changes to This Policy

We may update this policy from time to time. The effective date at the top of the page reflects the most recent revision. Continued use of Shikaku Daily after a change constitutes acceptance of the updated policy. For material changes, we will make reasonable efforts to notify users.