Cookies & storage policy
Effective 16 October 2026. What we store in your browser, why, and for how long.
1. Legal basis
Under the EU ePrivacy Directive (Dutch Telecommunicatiewet art. 11.7a), UK PECR and similar laws, storing information on your device needs consent unless it is strictly necessary for a service you asked for. Everything Mathidia Junior stores by default is strictly necessary. The only optional feature — voice answers — stays off until an adult turns it on below, and can be turned off again at any time.
2. Everything we store
| Name | Type | Purpose | Duration |
|---|---|---|---|
| sb-…-auth-token | Local storage | Keeps the parent signed in | Until sign-out (refreshed hourly) |
| Child session token | Local storage | Keeps a child signed in on a trusted device | 14 days or until sign-out |
| Device code | Local storage | Random code so a device you approved is recognised. Contains nothing personal. | Until browser data is cleared |
| mj_family_device | Cookie (first-party, secure, HTTP-only) | Remembers a device trusted with a Family Access code | Until revoked or cleared |
| mathidia.cookies | Local storage | Remembers you closed the cookie notice | Until cleared |
| mathidia.privacy | Local storage | Your privacy choices (voice answers on/off) and the date chosen | Until changed or cleared |
| Install-prompt flags | Local storage | Remembers whether you installed or dismissed the app prompt | Until cleared (dismissal resets after a few days) |
3. Third parties
- Our typefaces are served from our own website. No font, analytics or advertising service is contacted when you browse.
- Blog pictures may load from the image host named in an article, which receives your IP address but no page address (we send no referrer).
- Stripe sets its own strictly necessary cookies (fraud prevention) only on Stripe's checkout and billing pages, under Stripe's cookie policy.
4. What we do not use
No advertising cookies, no analytics or measurement cookies, no cross-site trackers, no social-media pixels, no fingerprinting for marketing, and no tracking of children.
5. Your choices
Essential storage (sign-in, device approval, these choices) is always on. There are no adverts or analytics.
Voice answers (optional, adults only): lets a child say an answer aloud. Your browser maker (for example Google in Chrome) may process the recording on its own servers. Currently: Off.
Choosing "Essential only" stops voice answers straight away on this device, including in other open tabs. Choices are stored per device.
6. Managing storage
You can clear cookies and site data in your browser settings at any time. Clearing them signs everyone out and removes device trust, so the next child sign-in on that device will need your approval again.
7. Changes and contact
If we ever want to use non-essential cookies, we will update this policy and ask for your consent first. Children's data will never be used for advertising. Questions: support@mathidiajunior.com. See also our privacy notice.
Official references
These are the primary sources our policies follow. We review them at least every 12 months, and sooner when the guidance changes; any change to our policies is approved by the service owner before it takes effect.
- ICO — Children's Code (UK) — The UK Information Commissioner's 15 standards for children's privacy, default settings, profiling, parental controls and age-appropriate design.
- FTC — COPPA compliance guidance (US) — US Federal Trade Commission guidance on parental consent, privacy notices, children's data, security and deletion, including the 2025 Rule amendments.
- European Commission — protection of minors under the DSA (EU) — Commission guidelines (July 2025) on the safety, privacy and protection of minors online under the Digital Services Act.
- UAE — child digital safety — UAE government guidance on child digital safety and the relevant UAE legislation.
- W3C — WCAG 2.2 (accessibility) — The Web Content Accessibility Guidelines standard used as the audit baseline for the learning experience.