Privacy Policy — HangeulMate

1. Introduction

CREAV ("we", "us", or "our") operates HangeulMate (hangeulmate.com). This Privacy Policy explains how we collect, use, and protect your personal information when you use our Service.

2. Information We Collect

Account Information

Email address (for account creation and communication)
Display name (chosen by you)
Google profile information (if you sign in with Google)

Learning Data

Lesson progress and quiz scores
Spaced repetition review history
XP, streaks, and achievement data
Learning goal preferences
K-pop/K-drama expression mastery progress
Explore favorites and flashcard review history
Daily quiz attempt counts

Voice & Audio Data

Microphone audio captured during pronunciation practice and voice chat (processed transiently, not permanently stored)
Speech recognition results (text transcriptions for pronunciation scoring)
For Premium AI users: audio transmitted to OpenAI Whisper for enhanced speech-to-text processing

Canvas & Input Data

Handwriting practice strokes (processed locally in your browser for character recognition; not transmitted to servers)
Typing game input and scores (stored locally)

Technical Data

Browser type and version
Device information
IP address (for security and analytics)

Payment Data

Payment processing is handled by Polar.sh and Stripe. We do not store your credit card numbers or bank account details. We receive only subscription status and billing period information.

3. How We Use Your Information

To provide and maintain the Service
To track your learning progress and personalize your experience
To process pronunciation evaluations and voice chat interactions
To manage your subscription and billing
To communicate important service updates (via in-app notices or email, when available)
To improve the Service based on usage patterns
To prevent fraud and ensure security

4. AI & Voice Data Processing

When you use AI-powered features (AI chat, voice chat, pronunciation evaluation, scene practice), the following data may be sent to OpenAI for processing:

Text messages you type in AI chat conversations
Audio recordings from voice chat and pronunciation practice (Premium AI tier)
Conversation context necessary for the AI tutor to respond appropriately

OpenAI processes this data according to their API data usage policy. We do not use your data to train AI models. Audio data is processed transiently and is not permanently stored on our servers or by OpenAI.

5. Data Storage and Security

Your data is stored securely using Supabase (PostgreSQL) with Row Level Security (RLS) policies ensuring you can only access your own data. Learning progress is also stored locally in your browser (localStorage/IndexedDB) for offline access and performance.

We use industry-standard security measures including HTTPS encryption, secure HTTP headers (CSP, HSTS, X-Frame-Options), and server-side authentication via Supabase SSR.

6. Third-Party Services

We use the following third-party services:

Supabase: Authentication and database (Singapore region)
Vercel: Web hosting and deployment
Google OAuth: Social sign-in
Polar.sh / Stripe: Payment processing
Google AdSense: Advertising (free tier only)
OpenAI: AI conversation, voice chat, pronunciation evaluation, and text-to-speech (Premium AI tier)
Cloudflare: DNS and domain management

Each third-party service has its own privacy policy. We recommend reviewing their policies.

7. Cookies

We use essential cookies for authentication session management. We do not use tracking cookies. Google AdSense (shown to free-tier users only) may use cookies for ad personalization as governed by Google's privacy policy.

8. Your Rights

You have the right to:

Access your personal data
Correct inaccurate personal data
Delete your account and associated data
Request export of your learning progress data
Revoke microphone access at any time through your browser settings

To exercise any of these rights, please contact us at support@hangeulmate.com.

9. Children's Privacy

HangeulMate is not intended for children under 13 years of age. We do not knowingly collect personal information from children under 13. If we become aware that we have collected such information, we will take steps to delete it.

10. Changes to This Policy

We may update this Privacy Policy from time to time. We will make reasonable efforts to notify you of material changes by posting a notice within the Service or updating the "Last updated" date above, which indicates the most recent revision.

11. Contact

If you have questions about this Privacy Policy, please contact us at support@hangeulmate.com.