Privacy

What the Site Counts

I want to know which lessons people read, how long they spend on them, and where they get stuck, so that I can make the lessons better. To learn that, each page reports a few facts back to this site, and to nobody else, while you read it. It sends the page’s address, how long the page was in front of you while you were using it, whether you finished one of its quizzes or coding challenges, the name of the site that linked you here, and whether you are on a phone, a tablet or a computer. The server adds the country your connection appears to come from.

Nothing is stored on your device for this, no cookie and no identifier. To count how many people visit in a day without one, the server combines your connection’s address and your browser’s description with the date and a random value that changes whenever the site is updated, and keeps only a short scrambled code made from them. The address and the browser description are never written down, and the code is different every day, so it can’t be used to follow you from one day to the next.

Where It Goes and How Long It Stays

These records are kept in Amazon Web Services’ CloudWatch logs in my own AWS account, and I use them only for totals on my own dashboard, such as visitors per day and the most-read lessons. They are deleted after 400 days. Like any web host, Amazon also keeps its own logs of requests to the site, and those do include addresses.

Your progress through the lessons is kept in your own browser’s storage, so the site can show you what you have finished. It isn’t sent to me.

Switching It Off

If your browser sends Global Privacy Control or Do Not Track, nothing is counted. You can also switch counting off for this browser here. That choice is the only thing this page stores on your device, and only once you make it.

Questions

If you have a question about any of this, you can reach me through the project’s repository.