Privacy Policy

1. Introduction

At Decilo, we take your privacy seriously. This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use our AI-powered English learning service. Please read this policy carefully.

2. Information We Collect

Personal Information

When you register, we collect:

• Full name
• Email address
• WhatsApp phone number
• Profession/industry
• Payment information (processed by Stripe)

Usage Data

We automatically collect:

• Messages and voice notes you send through WhatsApp for lesson purposes
• Learning progress and performance metrics
• Vocabulary review results
• Session timestamps and frequency of use

Voice Data

When you send voice messages, we process them using OpenAI's Whisper for transcription and analysis. Voice recordings are processed in real-time and are not permanently stored after analysis is complete.

3. How We Use Your Information

We use your information to:

• Provide personalized English lessons based on your profession
• Analyze your language skills and track your progress
• Generate AI-powered feedback on your pronunciation and grammar
• Send daily lessons and vocabulary reminders via WhatsApp
• Process payments and manage your subscription
• Improve our AI models and service quality
• Send important service updates and announcements
• Respond to your inquiries and provide support

4. Data Sharing

We share your data with the following third-party services:

• OpenAI: For AI processing of lessons and voice analysis. Subject to OpenAI's privacy policy.
• Stripe: For secure payment processing. We do not store your full credit card information.
• WhatsApp/Meta: For message delivery. Messages are end-to-end encrypted by WhatsApp.
• MongoDB Atlas: For secure database hosting in EU data centers.

We do not sell your personal information to third parties for marketing purposes.

5. Data Retention

We retain your personal data for as long as your account is active. If you delete your account, we will delete your personal data within 30 days, except where we are required to retain it for legal or regulatory purposes. Anonymized usage data may be retained for analytics and service improvement.

6. Data Security

We implement industry-standard security measures including:

• Encryption of data in transit (TLS/SSL) and at rest
• Secure authentication and access controls
• Regular security audits and monitoring
• EU-based data storage (GDPR compliant)

7. Your Rights (GDPR)

Under GDPR and applicable privacy laws, you have the right to:

• Access: Request a copy of your personal data
• Rectification: Correct inaccurate data
• Erasure: Request deletion of your data
• Portability: Receive your data in a portable format
• Objection: Object to certain processing activities
• Restriction: Request limited processing of your data

To exercise these rights, contact us at privacy@decilo.app. We will respond within 30 days.

8. Cookies and Tracking

Our website uses essential cookies for functionality and analytics cookies to understand how users interact with our site. You can control cookie preferences through your browser settings. Our WhatsApp-based service does not use cookies.

9. Children's Privacy

Decilo is not intended for users under 16 years of age. We do not knowingly collect personal information from children. If we become aware that we have collected data from a child, we will delete it promptly.

10. International Transfers

Your data may be processed by OpenAI in the United States. We ensure appropriate safeguards are in place, including Standard Contractual Clauses, for any international data transfers outside the EU.

11. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of significant changes via email or through the Service. The "Last updated" date at the top indicates when the policy was last revised.

12. Contact Us

For privacy-related questions or to exercise your rights: