Privacy
The short version: no accounts, no ads, no selling data. Your drill history lives in your own browser, and the site keeps only the minimum it needs to run.
What stays on your device
Drill progress — scores, streaks, per-category stats — is stored in your browser's localStorage only. It never leaves your device, and the drills page has a clear-history link that wipes it instantly. One functional cookie (NEXT_LOCALE) remembers your language choice; it identifies a preference, not a person.
Analytics
The site loads Vercel Analytics and Vercel Speed Insights to count anonymous page visits and measure real-world loading performance. These do not use advertising cookies and do not track you across other sites. There is no other third-party tracking, no ad network, and nothing is ever sold or shared for marketing.