Privacy
Updated
The short version: every calculation happens in your browser, and the numbers you enter are never stored or sent to us or anyone else. There are no accounts and no forms. The rest of this page explains the details.
Who runs Mathlark
Mathlark is run by Jon, based in Vermont, United States. For any question about this page or your privacy, email hello@mathlark.com.
Your numbers
When you type into a calculator, the math runs on your own device. Your numbers and results aren't sent to a server, saved in your browser, or included in analytics. Close the page and they're gone.
Share links
The Share button makes a link with your numbers in it, so someone else can open the same calculation. The numbers go in the part of the link after the # sign. Browsers never send that part to a server, so even when someone opens your link, the numbers stay between their browser and the link itself.
A share link is only created when you press Share. Anyone you give the link to can see the numbers in it, so share it only with people you're happy to show them to. On a phone or tablet, Share opens your device's share menu, and the app you choose handles the link from there.
Saved preferences
Mathlark remembers two choices in your browser's local storage so you don't have to set them on every page: your unit system (metric or imperial) and your currency symbol. They never leave your device, and they never include your numbers. You can remove them at any time by clearing this site's data in your browser settings.
Mathlark doesn't set any cookies.
Offline copies
So the calculators work without a connection, your browser keeps a copy of each Mathlark page you open, along with the files it needs to run. These are copies of the pages as we publish them, the same for everyone. They never include the numbers you enter, and they stay on your device.
Saving a calculator to your home screen is handled by your browser and your device. Nothing about it is sent to us. Clearing this site's data in your browser settings removes the saved copies, and removing the icon from your home screen removes the app.
Analytics
We use Cloudflare Web Analytics to count how many people visit each page, so we know which calculators are useful. It doesn't use cookies or store anything in your browser, and it doesn't track you across other websites. It never receives the numbers you enter.
Hosting
The site is hosted by Cloudflare. Like any web host, Cloudflare's servers receive the basic information every browser sends when it loads a page, such as your IP address and browser type, so they can deliver the page and protect the site from attacks. We don't use this to identify you.
Everything else the site needs, including its fonts, comes from Mathlark itself. Pages don't load scripts, embeds, or tracking pixels from other companies.
Ads
Mathlark doesn't show ads yet. We plan to add them to keep the site free. Before we do, we'll update this page to explain what the ad provider collects, and you'll be asked for your choice before any ad cookies are used. Ads will never receive the numbers you enter.
If you email us at hello@mathlark.com, we'll see your email address and whatever you write. We use it only to reply to you and to fix any problem you report. If your message includes a share link, it includes the numbers in that link.
Changes to this page
If what the site collects changes, we'll update this page before the change goes live and change the date at the top. Questions about privacy are welcome at hello@mathlark.com.