Privacy Policy

Last updated: October 2026

The short version

Periodic Bubbles has no accounts, no sign-ups and collects no personal information. Your preferences, collection, badges, quiz scores and streak stay on your own device. Anonymous usage events, such as a quiz being finished or a badge being earned, go to Google Analytics, but never names or anything you type.

Data stored on your device

We use your browser's localStorage to remember your preferences (sound on/off, colour key open/closed), your cookie choice, your popped-element collection, your Daily Bubble streak, your badges and your quiz scores. This data stays on your device, apart from the anonymous usage events described under Analytics, and is deleted if you clear your browser data. A service worker caches the app so it works offline.

Analytics

We use Google Analytics to understand how the site is used, for example which pages are popular and roughly where visitors come from. We also send a small set of anonymous usage events: a game, quiz, Daily Bubble or weekly challenge being started or finished (with the score or number of guesses), a badge being earned, which element or section page a link leads to, a printable teacher resource being printed or its Pinterest save link being clicked, the Daily Bubble reminder button, a practice round, a past puzzle, class mode or the share button being used, and a tip link being clicked. These events hold no names, typed text or accounts. Google Analytics sets cookies and collects usage data as described in Google's privacy documentation. You can opt out with the Google Analytics opt-out browser add-on.

Advertising

This site may display adverts served by Google AdSense. Google and its partners may use cookies to serve ads based on prior visits to this or other websites. You may opt out of personalised advertising by visiting Google Ads Settings. See how Google uses data from partner sites.

Your cookie choice

On your first visit a banner asks whether we may set analytics and advertising cookies. If you choose "Essential only", Google Analytics runs without cookies using Google's consent mode, and any adverts shown are non-personalised. The usage events described above are sent in the same way, without cookies. In the UK and Europe nothing beyond strictly necessary storage is set until you answer; elsewhere, the audience measurement described below may start when the page loads. Your choice is stored on your device and you can change it at any time using the "Cookie settings" link in the footer of every page.

Audience measurement

We use Mediavine Grow (grow.me) to measure how many people read the site and where they are, which advertising networks require before they will work with a publisher. Grow sets identifiers in your browser. In the UK and Europe it runs only after you allow cookies; elsewhere it runs when the page loads. See Mediavine's privacy policy.

Third-party content

Element photographs are loaded from Wikimedia Commons and images-of-elements.com. 3D atom models are loaded from Google's education storage, and fonts and icons are loaded from Google Fonts and jsDelivr. These services may log standard technical information (such as IP address) when your browser requests their content, governed by their own privacy policies.

Children

Periodic Bubbles is a general-audience educational site. We do not knowingly collect personal information from anyone, including children.

Contact

Questions about this policy? Email anthony@periodicbubbles.com or see the contact page.