Privacy Policy — 100% Local-First

Your study data belongs exclusively to you. We do not collect, store, transmit, or monetize your personal information.

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1. Our Core Privacy Philosophy

Most educational applications require account creation, collect your email address, track your geographic location, and log your study habits to sell targeted advertisements. Stopwatch for Study was intentionally architected on a Local-First privacy model. All software calculations, session timers, streak counters, and subject tags execute entirely inside your web browser. We do not maintain user databases, user accounts, or cloud telemetry.

2. Information We Do NOT Collect

When you access or use Stopwatch for Study, we do not collect:

  • Your name, email address, phone number, or contact details.
  • Your account credentials, passwords, or authentication tokens.
  • Your IP address, internet service provider, or precise geographic coordinates.
  • Your device hardware serial numbers or browser fingerprinting metrics.
  • Your financial information, payment card numbers, or billing history.

3. Client-Side Browser Storage (`localStorage`)

To provide persistent convenience (such as remembering your daily study streak, saving your recorded study sessions, and remembering your chosen study subject), Stopwatch for Study utilizes your browser's standard Web Storage API (localStorage).

The specific data points stored on your computer include:

study-sessions: Array of completed focus sessions (subject, duration, laps, timestamp).
streak-data: Counter tracking your consecutive daily study sessions.
selected-subject: The last study category you selected (e.g., Math, Science, History).

This data is stored purely on your physical device hardware and is never sent to our servers or any third-party infrastructure.

4. Web Audio API & Microphone Permissions

Our ambient sound system (rainfall, cafe murmur, brown noise) and audio alert chimes are generated purely using the HTML5 Web Audio API synthesis algorithms. The service never requests microphone, camera, or audio recording permissions. It only produces outgoing audio output when you intentionally interact with the player.

5. Zero Third-Party Trackers & Advertising

Stopwatch for Study does not run Google AdSense, Meta Pixel, Hotjar session recordings, or any commercial data brokerage scripts. Our codebase is free from tracking beacons, cross-site trackers, and behavioral profilers. We believe students deserve an ad-free sanctuary to study without surveillance capitalism.

6. Data Export & Permanent Deletion Rights

Because all data resides on your machine, you have complete ownership and sovereignty over your study records:

  • Export Anytime: You can download a complete CSV or JSON copy of your study history with one click in the Session History panel.
  • Instant Permanent Deletion: Clicking "Clear All History" instantly and irreversibly purges your stored sessions from your browser memory. Clearing your browser cache or cookies also resets all stored data immediately.

7. Children's Privacy (COPPA Compliance)

Stopwatch for Study complies strictly with the Children's Online Privacy Protection Act (COPPA) and GDPR-K. Because we do not collect, request, or store any personally identifiable information from any visitor, the website is completely safe for children, primary school students, and minors under the age of 13.

8. Contact & Questions

If you have questions regarding this Privacy Policy or our local-first architecture, please reach out to us at support@stopwatchforstudy.com.