Privacy Policy

SubjectLine Pro is committed to protecting your privacy. This policy explains how we handle data when you use our email subject line optimization tool.

Data Collection

We collect minimal data to provide our service:

• Form Inputs: Your email descriptions, audience information, and tone preferences are temporarily used to generate subject line suggestions
• Generated Results: Subject lines and analysis are displayed to you in real-time
• Usage History: Your past generations are stored only in your browser (using IndexedDB)

We do not collect:

• Personal identifiable information (name, email address, phone number)
• Account credentials (we have no login system)
• Analytics or tracking data
• Cookies for tracking purposes

Data Storage

All data storage is local-first and user-controlled:

• Browser Storage Only: Your generation history is stored in your browser's IndexedDB
• No Server Storage: We do not store your email content, descriptions, or generated subject lines on our servers
• You Control Your Data: You can clear your history at any time using your browser's developer tools or clear site data option

Data Retention

• User-Controlled: All stored data remains in your browser indefinitely until you clear it
• No Server Retention: Since we don't store data on servers, there's nothing to expire or delete on our end
• Clear Anytime: You can delete all locally stored data through your browser settings (Clear site data → IndexedDB)

AI API Disclosure

We use OpenAI's GPT-5-nano via Vercel AI Gateway to generate email subject line suggestions:

• Provider: OpenAI GPT-5-nano (accessed through Vercel AI Gateway)
• Purpose: Generate creative, optimized email subject lines based on your inputs
• Data Sent to AI:
  • Your email content descriptions
  • Target audience information
  • Tone preferences (professional, casual, urgent, etc.)
  • Selected email types and goals
• Processing: Your inputs are sent through Vercel AI Gateway to OpenAI only when you click "Generate Subject Lines"
• No Persistent Storage: OpenAI processes your request and returns results. Your data is not stored beyond the request/response cycle (see OpenAI's Privacy Policy)
• User Initiated: AI processing only happens when you explicitly click the generate button

Third-Party Services

We use the following third-party services:

• OpenAI GPT-5-nano (via Vercel AI Gateway): Used only when you generate subject lines (see AI API Disclosure above)
• No Other Services: We do not use analytics, tracking, advertising, or other third-party services

Your Rights

You have complete control over your data:

• Access: All your data is in your browser - you can view it anytime
• Delete: Clear your browser's site data to remove all locally stored information
• Export: Your generation history can be copied from the browser interface
• Opt-Out: Simply don't use the generation feature if you prefer not to send data to the AI API

Data Security

• HTTPS Encryption: All communication between your browser and our servers uses HTTPS
• No Server-Side User Data: Since we don't store user data on servers, there's no risk of server breaches exposing your information
• Local Storage Security: Your browser's IndexedDB is protected by same-origin policy

Children's Privacy

Our service is not directed at children under 13. We do not knowingly collect data from children.

Changes to This Policy

We may update this privacy policy occasionally. Changes will be posted on this page with an updated "Last Updated" date.

Transparency Commitment

We believe in radical transparency:

Your privacy is our priority.