Privacy

The short version: your scores stay on your device, and you choose how ads are shown to you.

What is saved on your device

QuantDrill uses your browser's local storage, which works like a cookie that never leaves your device. It holds:

• Your rounds: the score, date, settings and accuracy for each finished round, plus your three slowest answers.
• Your timing stats: how long, on average, each kind of problem takes you, used for weak spots and the heatmap.
• Your progress: milestones, daily challenge results, your goal, and the timeline of your best round for Race my best.
• Your preferences: your last settings, light or dark theme, timer bar choice and your ad choice.

This is needed for the features you use, so it is kept without asking. It is never sent to us or anyone else. You can delete it from the stats page or by clearing your browser data.

Ads and cookies

QuantDrill is paid for by ads from Google AdSense. Ads appear only between pages on the way to your results and at the bottom of the results page, never during a round.

When you first visit, you choose how ads are shown. If you choose Keep my scores, Google and its partners may use cookies to show ads, limit how often you see the same one, measure them, and tailor them to your interests. If you choose general ads only, Google shows ads that are not tailored to you, though it may still use cookies for things like frequency limits and fraud prevention.

Google explains what it does with this information on its page about how Google uses information from sites that use its services. You can also manage tailored ads at Google's ad settings.

Fonts and hosting

The site's fonts load from Google Fonts, which means your browser sends your IP address to Google to download them. Google Fonts does not set cookies. The site is hosted on Netlify, which keeps standard server logs, such as IP addresses, to run and protect the service.

Last updated 8 November 2026.