The short version
This site uses Google Analytics, Microsoft Clarity and Ahrefs Web Analytics to understand how visitors use it, and no other tracking. Advertising (Google AdSense) is not active yet. The only things stored in your browser without any tracking purpose at all are your light/dark theme preference and offline copies of pages you've opened, saved locally on your own device — they're never sent to us or anyone else.
What we store locally on your device
We use your browser's localStorage to remember your theme choice (light or dark) between visits, and whether you closed a tip such as the "rotate your device" hint. This stays on your device; we have no way to read it, and it's never transmitted anywhere.
The site also keeps copies of up to 60 pages you've opened (and the files they need) in your browser's cache storage, so you can read them again without internet. Nothing about this is sent to us. Clearing your browser's site data for periodicelementtable.com removes them.
Analytics
We use Google Analytics and Microsoft Clarity to see which pages get used, roughly how visitors reach the site, and to record anonymized interaction patterns (like where people scroll or click) that help us fix confusing or broken parts of the site. Both set cookies and collect standard analytics data (approximate location from IP address, device and browser type, pages visited); neither is used to identify you personally, and we don't combine this data with anything else about you. Visits from our Android app are labelled as app visits, so we can tell app and browser use apart. You can opt out of Google Analytics tracking site-wide using the Google Analytics Opt-out Browser Add-on, or block both simply by using your browser's tracking-protection or cookie-blocking settings — nothing on this site stops working if you do.
We also use Ahrefs Web Analytics to count page views and see which search engines and websites send visitors here. It doesn't set cookies or store anything on your device, and it reports only aggregated statistics such as page views, referring sites, country, device and browser type.
Server logs
Like virtually every website, our hosting provider automatically logs basic request information (IP address, requested page, browser type, timestamp) for security and operational purposes — this is standard web server behavior, not something we actively analyze or use to identify individual visitors.
Advertising (not yet active)
We intend to run Google AdSense once the site has steady traffic. The site is already registered with AdSense and configured with a Google-certified consent management platform, but ads themselves are not yet switched on. Once they are, visitors — especially those in the EEA, UK and Switzerland — will see a consent message before any advertising cookie is set, and this section (and the "last updated" date above) will be revised at the same time. Once active, Google and its advertising partners may use cookies to serve ads based on your prior visits to this or other websites; you'll be able to review and opt out of personalized advertising via Google's Ad Settings and learn more at Google's advertising policy page.
Children's privacy
This site is educational reference material that students of any age may use for schoolwork. We don't knowingly collect personal information from anyone, including children, and the site doesn't require an account, login, or any personal information to use.
Changes to this policy
If our practices change — most notably when advertising goes live — we'll update this page and the "last updated" date above.
Questions
Contact us at hello@periodicelementtable.com with any privacy questions.