Privacy — Cryptarithm
The game has no accounts, advertising scripts, or cloud progress service. We use Ahrefs Web Analytics and Google Analytics, with cookie choices based on your region.
Analytics and cookie choices
Ahrefs Web Analytics loads on the public site to measure visits, pages, referrals, language, device information, and link interactions. Ahrefs states that its default analytics does not use cookies. These requests send usage and connection information to Ahrefs.
For visitors in the European Economic Area, the United Kingdom, or Switzerland, Google Analytics 4 waits for permission. Elsewhere it loads by default unless you have declined. Cloudflare identifies the country from your IP address, not your interface language; the region endpoint returns only whether consent is required, not your IP or country. If detection fails, we ask for permission before loading Google Analytics.
When active, Google Analytics 4 uses cookies to measure visits and returning visitors; advertising storage, advertising personalization, and Google signals are disabled. Declining does not prevent you from playing. We do not send your saved answers or notes to either analytics service.
When Google Analytics is enabled, we also measure puzzle starts and completions, displayed completion time and check count, changes of puzzle type, operation or difficulty, editing-tool use, and share, copy and image-download actions. Events include the puzzle category and interface language, not entered digits, notes or puzzle IDs. Gameplay events are not sent to Ahrefs. Actions while Google Analytics is disabled are not saved for later reporting.
Your Google Analytics choice is stored for up to 180 days in localStorage under cryptarithm.analytics-consent.v1. Use Cookie settings in the footer to change your choice. Declining stops Google Analytics collection and removes its cookies on this site without clearing game progress; it does not remove data already received by the providers. Ahrefs cookie-free analytics remains active independently of this Google Analytics choice. Provider privacy policies are linked below. Automatic loading outside these regions is not saved as an explicit consent choice.
Data kept in your browser
The application stores puzzle history, entries, notes, timing, completion statistics, language preferences, and the sound setting in localStorage under cryptarithm.save.v1. Clearing site data removes this local copy.
Loading or refreshing a puzzle clears that puzzle’s active attempt, but preserves settings, historical completion statistics, and other saved puzzles.
What leaves the browser
Puzzle generation and ID restoration require a connection to our server. When you use Check or fill all cells, the puzzle ID and your entered digits are sent to the server for validation. The application does not store those entries on the server. QR and PNG creation stay on your device. A shared URL contains the puzzle ID, not your answers, notes, or elapsed time.
Your browser still requests pages, fonts, images, and sound files from the website host. The hosting provider may process connection information such as IP addresses and request logs under its own policies.
Downloads and external links
Downloaded images are saved on your device. Clipboard actions happen only when you request them. Following an external link takes you to a service with its own privacy practices.
We update this page when our data-handling practices change. For privacy questions, email feedback@cryptarithm.com.
Daily challenge privacy
One ranked attempt per browser identity each UTC day. Your player number, progress and score are public. Rankings compare floors first, then time.
An anonymous identity cookie lasts one year. Server records are kept for one year; entries and notes stay on this device. Clearing cookies or switching devices loses access. This casual leaderboard cannot prevent outside help or new identities.