There are no cookies, analytics, ads or accounts. Every calculation runs in your browser, and nothing you type is sent to a server.
Two preferences are saved in your browser’s local storage so the site remembers them:
brc.theme: light or dark theme.brc.sizes: decimal (MB) or binary (MiB) size units.
You can clear them at any time through your browser’s site-data settings. “Share link” puts your inputs in the URL so you can send them to someone; that only happens when you click it.
The site is served by a static host, which may keep standard server logs (such as IP address and requested page) for security and reliability.