Privacy Policy

The Short Version

All calculations happen entirely in your browser. We do not collect, store, transmit, or share any personal information or health data you enter into the calculators.

1. Information We Do Not Collect

GrowthPercentile.com is a client-side application. When you enter your child's weight, height, age, or sex into any calculator:

• The data stays in your browser
• No data is sent to any server
• No data is stored in any database
• No data is shared with any third party

We do not collect names, email addresses, IP addresses for tracking purposes, or any Protected Health Information (PHI) as defined by HIPAA.

2. Local Storage

The Site uses your browser's localStorage feature to store certain data on your device. This data never leaves your browser and is never transmitted to any server. Specifically:

2a. Visit Counter

A simple visit counter is stored to display a "visits" count on the dashboard. It contains no personal or health information.

2b. Growth Tracker Data

If you use the Growth Tracker feature, the following data is stored in your browser's localStorage:

• Child's first name (or any name you choose to enter)
• Child's sex (boy or girl)
• Child's date of birth
• Measurement entries: date, weight, height, and head circumference

This data is stored only on your device and is never:

• Sent to our servers or any third-party server
• Accessible to GrowthPercentile.com or its operators
• Included in any analytics or tracking
• Backed up or recoverable by us if lost

You are solely responsible for the data you enter and for the security of your own device. You can export your Growth Tracker data as a JSON file, import previously exported data, or permanently delete all stored data at any time using the controls on the Growth Tracker page.

If you clear your browser data, switch browsers, or use a different device, your Growth Tracker data will not be available — because it was never stored anywhere else.

2c. No Cookies

No cookies are set by the Site itself.

3. Third-Party Services

Hosting

The Site is hosted on Cloudflare Pages. Cloudflare may collect standard web server logs (IP address, browser type, pages visited, timestamps) as part of its infrastructure. This data is governed by Cloudflare's Privacy Policy.

CDN Resources

The Site loads the Chart.js library from a CDN (cdn.jsdelivr.net). This request is subject to jsDelivr's Privacy Policy.

Analytics

If analytics are added in the future, this policy will be updated to disclose the specific service used, what data is collected, and how to opt out. As of the last updated date above, no analytics service is active.

4. Children's Privacy

The Site is designed for use by parents, caregivers, and healthcare professionals — not by children directly. We do not knowingly collect personal information from children under 13 (or under 16 in the EEA). Since no personal data is collected from any user, this concern does not arise in practice.

5. Data Security

Because no personal or health data is transmitted to or stored on our servers, there is no server-side data to secure. The Site is served over HTTPS to protect the integrity of the page content delivered to your browser.

Data stored in your browser's localStorage (including Growth Tracker data) is protected by your browser's same-origin policy, which prevents other websites from accessing it. However, localStorage is not encrypted. Anyone with physical access to your device, or any browser extension you have installed, could potentially read this data. GrowthPercentile.com is not responsible for the security of your device, browser, or browser extensions.

If you are concerned about the security of locally stored data, you can:

• Use your browser's private/incognito mode (data is cleared when the window is closed)
• Export your data and delete it from the browser when not in use
• Clear your browser's localStorage at any time

6. Your Rights

Under GDPR, CCPA, and similar privacy regulations, you have the right to access, correct, delete, and port your personal data. Since we do not collect or store any personal data on our servers, there is no server-side data to access, correct, delete, or port.

All locally stored data (visit counter and Growth Tracker data) is under your full control:

• Access: View your Growth Tracker data directly on the Growth Tracker page
• Export / Portability: Use the "Export Data" button to download a JSON file of your data
• Delete: Use the "Delete Child" button or clear your browser's localStorage to permanently remove all data
• Correction: Delete and re-enter any incorrect measurements

Because this data exists only on your device, we cannot access, recover, or delete it on your behalf.

7. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be posted on this page with an updated "Last updated" date. If we begin collecting any personal data in the future, this policy will be updated before any collection begins.

8. Contact

If you have questions about this Privacy Policy, please contact us at [email protected].