How it works
- Write it. Text, images, files. Encryption happens in your browser, before anything leaves your device.
- Send the link. By mail, chat or text – whatever suits. Whoever holds the link can read it, so you can add a password and pass that along a different way.
- Then it is gone. After the pickup window the message expires by itself. Nothing to tidy up, nobody has to remember.
Why we cannot see the content
This is not a promise, it is how the thing is built. The key to your message sits in the link – behind the #. Everything after that character is never sent to the server by a browser. It keeps it, and decrypts only on the device that opens the link.
So all we hold is ciphertext. No employee can read along, no authority can demand anything legible, and a stolen database is worthless. Encryption is AES-256-GCM, the same method banks and governments use – and because tunnl. needs no asymmetric key exchange for the content, it also holds up against quantum computers. How that works in detail.
What people use tunnl. for
Payslips and invoices
Anything with an amount, an account number and a name on it. Whoever intercepts your invoice mail can send a second one with different bank details.
Passwords and access
The initial password for a new employee. The shop login. Otherwise both sit in a mailbox for ten years.
Papers for authorities and accountants
ID copies, debt register extracts, tax documents. Needed once, never again – and yet they stay forever.
Lists with people on them
Class lists, membership lists, patient data. These details are not yours; they were entrusted to you.
More examples – and what tunnl. is not good for.
What it costs
Sending a single message is free, with no account and no app. If you send confidential things regularly, there are two options: more room for attachments, longer windows, batch sending, groups, and your own company name on the page your recipient sees. Prices are in Swiss francs, billed from Switzerland.
And what tunnl. is not
Not an archive – what has expired is gone, for you too. Not a chat replacement: tunnl. is for what has to go from A to B once, not for the daily back and forth. And no protection against the recipient: whoever may read your message can photograph it. No technology prevents that, and we do not claim otherwise.
Common cases, one by one
- Sending payslips securely A payslip belongs to one person – and after sending usually sits in four mailboxes.
- Sending confidential documents by email Email is a postcard that gets copied. Confidential things need an envelope.
- Passing on a password safely The password does not belong in the same mail. And ideally nowhere it stays.
- An alternative to IncaMail Both send confidential things. They do not solve the same problem.
- Sending a file encrypted The attachment is too big for the mailbox – and too sensitive for a service that can look inside.
- Sending patient data and medical reports securely Health data is especially sensitive – legally and in everyday practice.
Security in detail · Compared with email, WeTransfer and Teams · Help · Who is behind this

