1. Introduction & Purpose

At Calcwillow ("we", "us", or "our"), accessible via https://calcwillow.com, we respect your privacy and are committed to protecting it. This Privacy Policy details our practices concerning data collection, local browser persistence, third-party infrastructure, and user data rights.

Unlike many modern web applications that monetize personal data or profile user activity, Calcwillow was engineered as an educational utility that operates completely in the client's browser environment.

2. Information We Do NOT Collect

To ensure complete user privacy, Calcwillow intentionally does not collect, harvest, or monetize the following categories of data:

• Personal Identifiable Information (PII): We do not ask for or store your name, email address, physical address, phone number, or academic institution.
• Calculation Inputs & Mathematical History: The formulas, algebraic expressions, numbers, functions, and trigonometric evaluations you enter are never transmitted to our servers or saved in any remote database.
• Scratchpad Notes: Notes, worked equations, and scratchpad text you write in the ruled notebook tool remain exclusively in your browser session and are never uploaded.
• Financial or Payment Details: Calcwillow is 100% free; we do not collect credit card numbers, billing information, or payment credentials.
• Location Data: We do not request or track precise GPS or geolocation data.

3. Information Stored Locally on Your Device (HTML5 LocalStorage)

Calcwillow uses standard HTML5 localStorage solely to provide convenience features across visits. This data remains on your physical device and is never synchronized to our servers:

How to delete this data: You can clear your notes at any time by clicking the trash icon (🗑️) on the scratchpad, or by clearing your browser's local storage and cookies via your browser's settings menu.

4. Standard Web Server Logs & Hosting Infrastructure

When you request any page or asset from https://calcwillow.com, the hosting infrastructure automatically records basic HTTP request metadata standard across the Internet. These server logs may include:

• Internet Protocol (IP) address (used solely for geolocation-agnostic DDoS protection and routing)
• Browser user-agent string and operating system architecture
• Referring webpage URLs and exit pages
• Date and timestamp of request

These logs are maintained strictly for network security, preventing automated bot abuse, and maintaining website reliability. They are never linked to personal identities.

5. Third-Party Services & Content Delivery

To ensure high page load speeds and visual aesthetics, Calcwillow utilizes trusted content delivery services:

• Google Fonts: Calcwillow loads modern typography (Inter, Outfit, Fira Code) via Google Fonts. When your browser requests font files, Google may receive your IP address in accordance with standard web protocols. You can view Google's Privacy Policy.
• Cloudflare / CDN: Content Delivery Networks cache static HTML, CSS, and JS assets to deliver lightning-fast response times globally.

We do not embed third-party advertising networks, surveillance SDKs, or social media tracking pixels.

6. Cookies and Tracking Technologies

Calcwillow does not use tracking cookies, advertising beacons, or web bugs. We do not use persistent marketing cookies to track your behavior across other websites.

7. Children's Online Privacy (COPPA & Student Safety)

Calcwillow is an educational mathematical tool widely used in classrooms, secondary schools, universities, and STEM study groups. We take children's privacy seriously and comply with the Children's Online Privacy Protection Act (COPPA) and GDPR-K:

• We do not knowingly collect any personally identifiable information from children under the age of 13 (or under 16 in the European Union).
• No student account creation or school email verification is required.
• Educators and parents can safely recommend Calcwillow without risk of data harvesting.

8. Your Rights Under GDPR, UK GDPR, and CCPA/CPRA

Depending on your jurisdiction (such as the European Economic Area, the United Kingdom, or California), you are entitled to specific privacy rights:

• Right to Know / Access: You have the right to know what personal data is processed. Because Calcwillow operates client-side, we store zero personal data on our servers.
• Right to Deletion: You have the right to delete your data. You can delete all locally stored calculator data instantaneously by clearing your browser cache.
• Right to Opt-Out of Data Selling or Sharing: Calcwillow never sells, rents, leases, or trades user data to third parties.
• Right to Non-Discrimination: All features of Calcwillow remain 100% accessible to all users equally.

9. Data Security

Calcwillow enforces end-to-end transport layer security using modern HTTPS / TLS 1.3 encryption. This ensures that all communication between your browser and our static servers remains tamper-proof and encrypted in transit.

10. Changes to This Privacy Policy

We may periodically update this Privacy Policy to reflect technical improvements or legal requirements. Any modifications will be posted directly on this page with an updated "Effective Date" at the top. We encourage you to review this policy periodically.

11. Contact Information

If you have any questions, feedback, or inquiries regarding this Privacy Policy or Calcwillow's data privacy practices, please contact us at: