Privacy note

• No upload. Calculator inputs and CSV files are processed by JavaScript on your device. Closing the tab clears them.
• No network requests carrying your data. Each tool page sets a Content-Security-Policy that blocks fetch, XHR and similar to any other site. The only outside address it allows is Cloudflare's analytics endpoint (below). Sample CSVs are built into the page, so even those don't need a download.
• No accounts, no email gate, no paywall. The tools are free to use fully.
• Analytics: Cloudflare Web Analytics (cookieless, aggregate). To see whether anyone uses these pages, the site uses Cloudflare Web Analytics. It sets no cookies, uses no local storage and doesn't fingerprint you or track you across sites. When a page loads, a small Cloudflare script (static.cloudflareinsights.com) reports the page address, the referring site, your browser and device type, your country (worked out from the connection) and page-load timings to Cloudflare. I only see totals, such as page views per page, top referrers and countries. I never see anything that identifies you. It never receives the numbers you type or the files you open: those stay in your browser. Cloudflare's own description: cloudflare.com/web-analytics and Cloudflare privacy policy. Content blockers that block it don't break anything. (Added 9 Oct 2026.)
• Outbound links. Links to Contra, Etsy or other sites (when present) leave this host. Their privacy policies apply there. Product links may include UTM tags so I can see which free tool a sale came from; those tags don't contain your data.
• Hosting. The static files are served by Cloudflare Pages. Cloudflare's network may see the usual connection metadata for any website (IP address, user agent, pages requested). Apart from the aggregate analytics above, I don't run any tracker.

Questions: contact Chris Elder via his Contra profile.