Cookie Policy

Last updated: April 2026

This policy explains how AllergyScan uses cookies and similar browser storage technologies. We aim to use as few tracking technologies as possible and to be fully transparent about what we do use.

What Are Cookies?

Cookies are small text files that a website stores on your device. They are used to remember information between page loads and sessions. We also use localStorage, a similar browser mechanism that stores data locally on your device without sending it to a server.

What We Use

Authentication CookiesRequired

When you sign in to AllergyScan, our authentication provider (Supabase) sets session cookies to keep you logged in. These cookies are strictly necessary for the service to function — without them, you cannot maintain a signed-in session. They are automatically cleared when you sign out.

Name pattern: sb-*
Purpose: Maintain your signed-in session
Expires: End of session, or when you sign out
Third party: Supabase Inc.

Theme PreferenceRequired / Functional

We store your colour theme preference (dark or light mode) in your browser's localStorage. This is not a cookie — it stays entirely on your device and is never transmitted to our servers. It simply remembers whether you prefer the dark or light interface.

Key: theme
Purpose: Remember your display preference
Expires: Until cleared manually (localStorage persists across sessions)
Third party: None

AnalyticsNon-identifying

We use Vercel Web Analytics, a privacy-first analytics tool. Unlike traditional analytics platforms, Vercel Web Analytics does not set any cookies and does not collect personally identifiable information. It uses hashed IP addresses and browser attributes to count unique visitors without tracking individuals across sites or sessions.

Cookies set: None
Purpose: Understand aggregate usage patterns (page views, general region)
Third party: Vercel Inc.

What We Do Not Use

AllergyScan does not use:

  • Advertising or targeting cookies
  • Social media tracking pixels
  • Third-party behavioural tracking tools
  • Cross-site tracking of any kind

How to Manage Cookies

You can clear cookies and localStorage at any time through your browser settings. The steps vary by browser — look for "Clear browsing data" or "Privacy & Security" in your browser's settings menu.

Note: clearing authentication cookies will sign you out of AllergyScan. Clearing localStorage will reset your theme preference to the system default.

Because we only use strictly necessary cookies (for sign-in) and non-cookie analytics, there is no cookie consent banner. If we ever introduce optional cookies in the future, we will update this policy and add appropriate consent controls.

Changes to This Policy

We may update this policy if we change the technologies we use. We will update the date at the top of this page when we do.