Updated October 5, 2026

Privacy

elhelali.dev is a free, animated companion to An Introduction to Statistical Learning, made by Ali Elhelali. This page says what it stores and why. Nothing is sold, and there are no ads or third-party trackers.

Without an account

Your reading progress and the code you write stay in your own browser (local storage). They never leave your device unless you sign in. Python runs in your browser too; your code is not sent to a server to run.

If you sign in with Google

Google shares your name, email address and profile picture with us. We use them to recognise you and to show your name on your account menu. We then store your progress (which scenes you finished) and the code you wrote in the exercises, so they follow you between devices.

One cookie keeps you signed in for up to 30 days. It holds a signed reference to your account, nothing else.

Your public page

Nothing about you is public unless you publish a portfolio page. If you do, it shows the name and picture from your Google account, the handle and headline you chose, your progress and, if you allow it, your exercise code. Your email is never shown. You can unpublish at any time and the page disappears.

Asking the tutor

Questions you ask, and the page section they are about, are sent to OpenAI to write an answer, and checked by OpenAI’s moderation service. Questions and answers are saved and shown to other readers under “Asked before”, labelled only with an approximate place (such as a US state, or a city and country) taken from your connection. Your IP address is not stored; to enforce a daily question limit we keep a one-way hash of it that changes every day.

If you report a mistake, the question and answer are emailed to the author through our email provider, Resend.

Where it lives

The site and its database run on Cloudflare. Google (sign-in), OpenAI (tutor) and Resend (error reports) receive only what is described above.

Deleting your data

Signing out removes the cookie. To delete your account, progress and code, email elhelali-learning@googlegroups.com from the address you signed in with, and it will be removed within 30 days.

Contact

Questions about this policy: elhelali-learning@googlegroups.com.