Sealed Messages
Send end-to-end encrypted messages that are automatically destroyed after reading.
What is Flaschenpost?
Flaschenpost is a secure channel for confidential one-time messages. The message is encrypted directly in your browser before being sent. The decryption key is only contained in the link and is never stored on our servers. Once the message is read or expires, it is irrevocably deleted.
End-to-End Encryption
Flaschenpost uses AES-256-GCM encryption. The key is only transmitted as a URL fragment (#) and never reaches our servers. Even we cannot read your messages.
Features
Client-Side Encryption
The message is encrypted in your browser before it reaches our servers. The key stays with the sender.
View Limit
Set how many times the message can be viewed (1-100 times). It is automatically deleted after that.
Auto-Expiry
Set an expiry date: 1 hour, 24 hours, 7 days, 30 days, or no limit.
Reply Feature
Allow the recipient to reply with encryption. Replies require login.
How It Works
Write Your Message
Write your secret message and configure security options: password, view limit, and expiry date.
Create Flaschenpost
The message is encrypted locally in your browser. You receive a link with the decryption key in the fragment.
Share the Link
Send the link to the recipient. Optionally: share the password through a separate channel.
Message is Read
The recipient opens the link, enters the password if required, and sees the decrypted message. You will be notified.
Create Flaschenpost
The creation form allows you to configure all security options for your encrypted message.
Create New Flaschenpost
Write a message that will be destroyed after reading.
This message will be transmitted encrypted.
Settings
Share the password through a different channel.
How many times can the message be viewed?
Allow Replies
Recipients can reply (requires login).
Message Overview
Manage all sent Flaschenpost messages in one place. View status, views, and replies.
Sent
Your sent Flaschenpost messages
Recipient View
How the recipient sees your Flaschenpost message - password protected or directly decrypted.
With Password Protection
Password Required
This message is password protected.
Decrypted Message
Secret Message
From John Doe (Example Inc.)
Hello, this is a confidential message that will be automatically deleted after reading. Best regards
Secure messages with SendMeSafe
Detail View & Replies
Track the status of your Flaschenpost and read incoming replies.
Flaschenpost Details
Created Jan 28, 2026, 2:30 PM
0 / 1
1
Yes
In 2 days
The encryption key is contained in the link fragment.
Replies (1)
Jane Smith
Partner Corp
The reply is end-to-end encrypted.
About Flaschenpost
Flaschenpost messages are end-to-end encrypted. The key is only contained in the shared link and is never stored on our servers.
Use Cases
- Secure transmission of passwords, API keys, or credentials to colleagues or clients
- Send confidential information to business partners that should only be read once
- Share sensitive document instructions that disappear after reading
- Short-term communication with high confidentiality, e.g., during M&A transactions
Tips
- Always share the password through a separate channel (e.g., phone, SMS)
- Use short expiry times for particularly sensitive information
- Enable the reply feature if you need confirmation from the recipient
Flaschenpost is available from the Starter plan. The reply feature also requires at least a Starter plan.