Privacy

This site has no accounts, no sign-up, and collects no personal information. What follows describes exactly what it does store and what it sends elsewhere.

Last updated: 9 October 2026 — added the Usage statistics section (search log and Cloudflare Web Analytics) and eBay alongside Rakuten.

What this site stores about you

One thing: your language preference (English or Japanese) is saved in your browser's localStorage under the key cpc.lang, so the page opens in the language you chose last time. It never leaves your browser, and clearing your browser data removes it.

There are no accounts, no login, no newsletter, and no contact form. One exception to "nothing you type leaves the page": search queries are logged for usage statistics — see the next section.

Usage statistics

Two privacy-preserving measures are in use:

• Search log (server-side). Each search you run records one line containing: which market button was used (Rakuten or eBay US), the words you typed, and the coarse location Cloudflare attaches to the request (country, region, city). It does not record your IP address, set any cookie, or carry any identifier that could tie one search to another. The purpose is solely to see how much the site is used and from which countries.
• Cloudflare Web Analytics. A cookieless page-view counter provided by the hosting platform. It reports aggregate page views, referrers, countries, and device types without tracking individual visitors. See Cloudflare's description of the service.

What is sent to third parties

Rakuten and eBay

When you run a search, the words you typed are sent to the Rakuten Ichiba product API or the eBay Browse API (depending on the button you used) so it can return matching products. The request is made by this site's server-side function, not by your browser, so Rakuten and eBay do not receive your IP address or browser details from that call. The search term itself is transmitted, because it is the query. Do not enter personal information into the search box — it has no purpose there and would be sent to the retailer along with the rest of the query.

Hosting

The site is hosted on Cloudflare Pages. Like effectively all web hosts, Cloudflare processes standard request data such as IP address and user agent in order to serve the page and protect against abuse. That processing is governed by Cloudflare's own privacy terms, not this project's.

Advertising

This site may display advertising supplied by Google AdSense. Where advertising is enabled:

• Third-party vendors, including Google, use cookies to serve ads based on your prior visits to this and other websites.
• Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and/or other sites on the internet.
• You may opt out of personalised advertising by visiting Google Ads Settings. You can opt out of a third-party vendor's use of cookies for personalised advertising at aboutads.info.
• Further detail is in Google's policy on how it uses information from sites that use its services.

Google’s advertising script is loaded on every page of this site. It is required both to serve ads and for Google to verify the site, so it runs whether or not an ad is currently displayed. It may set cookies as described above. Ad units themselves appear only where the site has been configured to show them.

Visitors in the EEA and the UK

Visitors in the European Economic Area, the United Kingdom and Switzerland are shown a consent message before advertising cookies are set, using Google’s certified consent management platform. You may accept or decline, and you can change your choice later through the privacy link Google adds to the page. Declining does not affect the calculator, which works the same either way.

Links to retailers

Product links point to Rakuten's or eBay's own pages. Once you follow one, you are on the retailer's site and their privacy terms apply. This site does not currently use affiliate links and earns nothing from any purchase you make.

Children

This site is not directed at children and does not knowingly collect information from anyone.

Changes

If this policy changes — for example if analytics or affiliate links are introduced — the date at the top of this page will be updated to say so.

Contact

Questions about this policy can be directed through the project site.