Where Thoughts Stay Private
The only note-taking app with military-grade encryption and private AI that never sees your data.
Think freely without compromise
Black Box Diary gives you the power of AI-assisted note taking with the privacy you deserve
Smart Meeting Notes
200 free minutes: Automatic meeting summaries and action items
AI-Powered Tools
Enhance, summarize, and perfect your notes automatically
Intelligent Organization
Group notes with tags, filter easily, and pin important notes
Instant Search
Find anything in your notes with pinpoint accuracy
Privacy matters
No need to join as robots in meetings. Keep it open in background and take your meetings
Military-Grade Encryption
AES-256 encryption with zero-knowledge architecture
Free Tier
20 notes + 200 meeting minutes with no credit card required
Access Anywhere
Access your encrypted notes on all devices anywhere 24/7
End-to-End Encryption
Your notes are encrypted before they leave your device. Not even we can read them.
AI that understands you
Our proprietary encrypted AI architecture learns from your notes without ever seeing the raw data.
Smart Organization
Automatically tags and categorizes your notes for easy retrieval
Instant Search
Find anything in your notes with pinpoint accuracy
Meeting Insights
Identifies action items and key decisions from your meeting notes
Privacy by design, not by accident
Black Box Diary is built from the ground up to protect your most sensitive thoughts with multiple layers of security.
Zero-Knowledge Architecture
Your data is encrypted with keys only you possess.
AES-256 Encryption
Military-grade encryption secures your data at rest and in transit.
On-Device Processing
AI features process data locally whenever possible to preserve privacy.
Trusted by forward-thinking teams
Join thousands of professionals who trust Black Box Diary with their most important thoughts
Sarah J.
"Black Box Diary has completely transformed how I organize my thoughts. The AI suggestions are incredibly helpful without ever making me worry about privacy."
John white
"As someone who deals with sensitive business strategies daily, the encryption gives me peace of mind. The meeting transcription feature is a game-changer."
Priya K.
"The encrypted search works so well it feels like magic. I can find any note instantly without compromising security. Essential for my research work."
Simple, transparent pricing
Choose the plan that fits your needs. Cancel anytime.
Free
- 10 notes limit
- 60 meeting minutes/month
- Basic AI suggestions
- Cross-device sync
- Unlimited notes
- Unlimited meetings
Premium
- Unlimited notes
- Unlimited meeting minutes
- Advanced formatting
- Enhanced AI features
- Meeting transcripts
- Priority support
Pro
- Everything in Premium
- Unlimited meeting minutes
- Advanced formatting
- Enhanced AI features
- Meeting transcripts
- Dedicated support
Need custom features or team pricing? Contact our sales team
Frequently Asked Questions
Everything you need to know about Black Box Diary
Black Box Diary uses end-to-end AES-256 encryption with zero-knowledge architecture. Your notes are encrypted on your device before they ever reach our servers. Not even our team can access your data.
Our AI processes your data using most powerful OpenAI model to extract as much information as we can. if you have any questions regarding which tool we use for AI process please contact our customer care team.
As we cannot search encrypted notes directly, we use a unique mechanism to ensure your privacy remains same and get you the exact note you are looking for.
The free tier includes:
- Up to 20 private notes
- 200 minutes of meeting transcription per month
- AI suggestions and organization
- Customer support
Due to our zero-knowledge architecture, we cannot recover your password or decrypt your data if you lose it. We strongly recommend:
- Using forgot password from login page
- Due to security concerns we are not allowed to change any customer password ourselves
Still have questions?
Ready to think freely?
Join thousands of professionals who trust Black Box Diary with their most important thoughts and ideas.
No credit card required • start free trial