Send anything.
We see nothing.
End-to-end encrypted in your browser. The key never reaches our server.
Drop a file in the panel - or anywhere on this page.
How it works
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You drop a file.
We never know what it's called.
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Your browser encrypts it.
We never have the key.
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We store ciphertext.
We can't read it. Not for police, not for ourselves.
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The recipient decrypts in their browser.
The key never reaches our server.
Tessil, explained
Tessil is an end-to-end encrypted file transfer service.
Files are scrambled in your browser before they leave your
device. The decryption key lives in the URL fragment of the
share link, the part after # that browsers
don't send to servers. We never see your files, your
filenames, or your keys.
You don't have to take that on faith. Verify it yourself walks through four checks you can run against this site in about two minutes, using the developer tools already in your browser.
Anonymous transfers expire in hours; signed-in transfers can run longer and live on your dashboard. Password protection adds a second factor independent of the link. Read more about the security model on the security page.
New to encrypted transfer? See how Tessil compares to WeTransfer, Proton Drive, and other tools.
Built and run by one person, and free to use. If Tessil saves you a headache, you can support the project. The link's in the footer below.
Frequently asked questions
Is Tessil really end-to-end encrypted?
Yes. Your files are encrypted in your browser with AES-GCM before they upload, and the decryption key lives in the share link, never on our servers. We can't read your files, your filenames, or your keys.
Do I need an account to send files?
No. You can send and receive files anonymously. A free account is optional and just adds a dashboard to manage the transfers you create. It doesn't change how files are encrypted.
How is Tessil different from WeTransfer or Dropbox?
Those services can read what you upload. Tessil can't, because encryption happens in your browser before anything is sent. Tessil is also open source, EU-hosted, and shows no ads. See the full comparison.
How large can the files be?
Large files are supported through multi-part uploads, so big transfers stay reliable even on slower connections. Signed-in transfers allow larger sizes than anonymous ones.
Is Tessil free?
Yes, completely free, with no ads and no selling of data. Tessil is open source under the AGPL-3.0 licence, so anyone can audit exactly how it handles encryption.
How long do transfers last?
Transfers expire automatically based on the time limit and download count you choose. Once a transfer expires, the encrypted data is deleted.