Useful without building a profile of you.

Browser-only lists

Without an account, your named lists are stored only in this browser using local storage. They are not transmitted to Residue Lens. Clearing site data removes them. Export and import happen only when you choose a file; shopping-mode ticks reset when the page closes.

Optional account sync

When account services are connected and you sign in, nothing is uploaded automatically. “Upload this device” sends your named lists and food identifiers to the account database; “Load cloud lists” replaces the browser copy after you choose it. Identity is handled by the configured authentication provider.

Requests, feedback and interest

When the private inbox is connected, food requests and feedback are stored for product review. Feedback may include an optional reply email. Waitlist forms require an email so an update can be sent. Each form reports if the inbox is unavailable; failed submissions are not silently presented as received. Free text is not copied into audience analytics.

Audience measurement

On a Vercel-hosted preview or release, the site uses Vercel Web Analytics and Speed Insights for aggregate page use and performance. Actions such as saving or exporting a list may send an anonymous named event. No advertising cookies are installed by this app. Local development does not normally send those measurements.

Payments

Residue Lens Plus is not currently on sale and the public site does not offer checkout. The payment foundation remains dormant for possible future testing. If paid access is introduced, its price, terms and payment provider will be shown before any payment decision. Existing test subscription records can still be managed through the account page.

Last updated: 16 September 2026.