Storage / Cookie / External Transmission Notice
This page explains the browser storage and external transmissions used by the Knowtopia website. It is intended to help users in Japan understand how the site works and to support our disclosures under applicable privacy and telecommunications rules.
In Short
- We use browser storage to keep the site working, including cart, language, sign-in, and checkout recovery.
- If you use login, checkout, or embedded video, limited information is sent to service providers such as Google/Firebase, Stripe, Sanity CDN, and YouTube.
- We do not currently use personalized advertising cookies on this website.
More About Browser Storage
Open this section if you want a more detailed breakdown of the browser storage used on the site.
Cart contents
Stores cart contents so checkout works across page changes and reloads.
- Retention
- Until you clear the cart or browser data.
- Category
- Necessary
Language preference
Remembers your selected display language.
- Retention
- Until changed or browser data is cleared.
- Category
- Necessary
Signed-in session
Keeps the signed-in state and authentication handoff working.
- Retention
- Until sign-out, SDK fallback change, or browser data is cleared.
- Category
- Necessary
Checkout recovery
Temporarily stores Stripe session ids so an order can be recovered after login or redirect.
- Retention
- Up to 7 days, or until the order is recorded, whichever comes first.
- Category
- Necessary
Google redirect helper
Temporary session-scoped flags used to complete Google sign-in or Google account linking after redirect.
- Retention
- Short-lived session storage; normally removed when the flow completes or the tab/session ends.
- Category
- Necessary
Notice close preference
Remembers that you closed this notice.
- Retention
- Until browser data is cleared or the notice version changes.
- Category
- Necessary
QR campaign measurement
Stores the QR / campaign code, landing path, referrer, and UTM data for first-party measurement of postcard and QR campaigns.
- Retention
- 30 days.
- Category
- Limited first-party measurement
QR duplicate-prevention id
Stores a rotating pseudonymous identifier to avoid overcounting the same QR visitor.
- Retention
- 30 days.
- Category
- Limited first-party measurement
Technical key names
Exact browser storage identifiers used by the site.
- Cart contents
knowtopia-cart - Language preference
knowtopia:language - Signed-in session
Firebase Authentication browser persistence (SDK-managed) - Checkout recovery
knowtopia.pendingOrderSessionIds - Google redirect helper
knowtopia.googleSignInRedirectPending / knowtopia.googleLinkRedirectPending - Notice close preference
kt_cookie_notice_dismissed_v2 - QR campaign measurement
kt_qr_attribution_v1 - QR duplicate-prevention id
kt_qr_device_v1
More About External Services
Open this section if you want to see which providers are involved and when data is sent.
Google / Firebase
- When it happens
- When the site initializes authentication, and when you use sign-in or account features.
- Data sent
- IP address, browser / device information, SDK-managed auth/session information, and if you sign in, account identifiers needed for authentication.
- Purpose
- Authentication, session persistence, and account security.
- How to avoid / control
- Avoid sign-in features if you do not want this transmission. Blocking browser storage/cookies may break login.
Stripe
- When it happens
- When you start checkout, open the billing portal, or recover a payment session.
- Data sent
- IP address, browser / device information, order identifiers, checkout session ids, and payment/shipping details that you enter on Stripe pages.
- Purpose
- Payment processing, receipts, billing management, and fraud prevention.
- How to avoid / control
- Avoid checkout / billing portal features if you do not want this transmission.
Sanity CDN
- When it happens
- When pages load product or content images hosted on the Sanity CDN.
- Data sent
- IP address, browser / device information, and the requested asset URL.
- Purpose
- Image and content asset delivery.
- How to avoid / control
- Blocking this transmission may prevent product or support images from loading.
YouTube (youtube-nocookie.com)
- When it happens
- Only after you click play on an embedded video.
- Data sent
- IP address, browser / device information, and the requested video id.
- Purpose
- Video playback.
- How to avoid / control
- Do not click play if you do not want the transmission to YouTube.
How To Control It
- You can clear site data in your browser to remove local storage entries.
- Blocking cookies/site data may prevent sign-in, checkout recovery, or language/cart persistence from working.
- Do not click embedded video play buttons if you do not want data sent to YouTube.
- Do not use login or checkout features if you do not want data sent to Google/Firebase or Stripe.
Contact
If you have questions about this notice or Japanese privacy compliance, contact us via the Privacy Policy contact details.
Last updated: 2026-03-11