Privacy policy

PT Charts (ptcharts.com) is a free reference site. This page explains what data the site collects and why.

What we collect

Our hosting provider, Cloudflare, processes standard request logs (IP address, browser, requested page) to deliver and protect the site.

The calculators run in your browser. The values you enter are not sent to us. They appear in the page address only so you can share or bookmark a result.

Some choices you make on the site, such as your state or your usual settings, are remembered in your browser's local storage on this device so the tools start where you left off. They are never sent to us; clearing this site's data removes them.

A few picks last only for your current visit: they are kept in your browser's session storage and disappear when you close the tab.

So the site works without a connection, your browser keeps a copy of its pages and files. It holds no personal data; clearing this site's data removes it.

Analytics

We use Umami, an analytics tool we run ourselves, to count page views and see which pages and tools are used. It does not use cookies, does not fingerprint visitors and does not track you across other sites. We never see the values you enter in a tool.

Google Analytics

We use Google Analytics 4 to learn how the site is used: which pages and tools people use, how they found the site (for example a search engine or a link), their approximate location (country and city), and their type of device and browser. We also record a few events of our own: that a tool was used on a page, that a product page was viewed or its buttons clicked, and, if you buy something, the product and the amount. We never send the values you enter in a tool, your name, your email address or your download links, and page addresses are sent without their query string.

If you allow it, Google Analytics sets two cookies on this site: _ga, a random identifier that tells repeat visits from the same browser apart, and _ga_EX7D8J40X5, which keeps track of the current visit. Both expire 13 months after your last visit.

Google processes this data on our behalf, as our data processor. Google Analytics 4 does not log or store IP addresses. We keep Google signals and ad personalization turned off, we don't link Google Analytics to any advertising product, and we don't use the data for advertising. Google Analytics keeps the event data for 14 months and then deletes it.

Visitors in the European Economic Area, the United Kingdom and Switzerland, and anyone whose location we can't tell, are asked first: Google Analytics loads only after you choose Accept. Elsewhere it loads unless you turn it off. If your browser sends a Global Privacy Control signal, Google Analytics stays off wherever you are. To find out where to ask, the site checks which country your connection comes from. Your browser keeps that answer in its session storage for this visit only (it is gone when you close the tab) and never sends it back to us.

You can change your choice at any time with Privacy choices at the bottom of every page. Declining stops Google Analytics and deletes its cookies from this site. Your choice is saved in your browser's local storage, not in a cookie, and is never sent to us. If you clear this site's data, we ask again.

To ask about, or ask us to delete, analytics data about you, write to the address under Contact below.

Purchases

When you buy a product, Stripe processes the payment on its own checkout page. We never see or store your card number. Stripe tells us your email address, the amount and what you bought. We keep that record to deliver your download, to answer questions about your order, to handle refunds and for our tax and accounting records. We email you only about that order. Stripe's own privacy policy covers what it collects.

Email sign-up

If you sign up for email from this site, we collect your email address, the list you joined, the sign-up wording you agreed to, the page you signed up on (without its query string) and when. To stop abuse we also keep a one-way hashed form of your IP address, not the address itself. We use your email address only to send what that list promises.

We first send one email with a confirmation link. You're not added, and we send nothing more, unless you click it. Every email we send has an unsubscribe link that works in one click, or write to the address under Contact below and we'll remove you.

Sign-ups are kept until you unsubscribe. After that we keep the address, marked unsubscribed, so we don't email you again; contact us to have it erased.

Sign-ups are stored by Keystone, a service Rocky Mountain Apps runs on its own server (keystone.rockymountainapps.com). Our email delivery provider, Resend, sends the messages on our behalf. We never sell your address or share it for anyone else's own use.

What we don't do

We don't sell personal data, we don't share it for advertising, and we don't use advertising cookies on this site at this time. The Google Analytics cookies described above are used only to measure this site. If that changes, this page will say so first.

Contact

Questions about privacy: hello@ptcharts.com.