Privacy
The short version: everything you type stays in your browser, and this page explains exactly what Numerus does and does not do with your data.
What happens to the numbers you type
Nothing leaves your device. The converter, the charts and the date generator all run as code in your browser. Numbers, numerals and dates you enter are never uploaded, stored or logged by us.
Cookies and local storage
Numerusitself stores one thing on your device: your light or dark theme preference, kept in your browser's local storage so the site remembers your choice. You can clear it at any time through your browser settings. If third-party advertising or analytics is active on this site, those providers may set their own cookies, described below.
Advertising and analytics
Numerus may show ads served by third-party advertising networks (for example Google) to help keep the site free. When advertising is enabled, those networks and any analytics tools used alongside them can set cookies or use similar technology to select and measure ads, understand aggregate traffic, and prevent fraud. If you are visiting from the European Economic Area or the United Kingdom, you will be shown a consent banner and asked for your choice before any non-essential cookies are set or personalized ads are shown. You can decline and still use the converter and every reference page.
Hosting
Numerus is served as static pages from Vercel. Like any web host, Vercel processes standard technical request data (such as IP address and browser type) to deliver pages and keep the service secure. See the Vercel privacy policy for details.
The JSON API and the embeddable widget
The free JSON API serves prebuilt static responses; requests pass through the same standard hosting logs described above and nothing else. The embeddable widget converts entirely inside the iframe on the host page and sends nothing back to us.
Contact form
The contact page sends your name, email address and message to us so we can reply. It is the only way to reach us; we do not publish an email address. That information is used only to answer your message.
Changes
If the way the site works ever changes in a way that affects your privacy, including turning on advertising or analytics, this page will be updated to describe it accurately.