All frequently asked questions on one page
Why does this service exist?
We strive to make sharing files over the internet as easy and as secure as possible. Sharing files by e-mail is only possible if file sizes stay small. In addition, e-mail messages and and e-mail attachments are almost never encrypted. This service is required to share larger files and to stay secure.
Why is encryption important?
By encrypting files we assume that third parties can't read them. This is important, among other things, for protecting the right to privacy, freedom of the press and data protection.
What is the current maximum supported file size?
We currently support encrypted filesharing up to 500 MB per upload.
What is the most secure way to share files?
We recommend users to use secure web browsers. When you visit this website in a secure web browser files will be encrypted before being uploaded.

In addition, we recommend users to set a password during the upload process. The given password will be used to derive an encryption key. The given password will never be sent over the internet.

After you have submitted files you can share the password with the recipient in person, without the use of the internet, or via an e-mail or chat service that utilizes end-to-end encryption (ProtonMail, WhatsApp, Telegram).
When will the decryption key that is required to download files be shared over the internet?
The decryption key will only be shared with our servers in certain circumstances. The password that you submit during the upload process will never be shared.

  • When you enter an e-mail address in the Recipient field the encryption key will be shared if you have not set a password. In this case the recipient will need the decryption key to download the files.
How do I know if I am using a secure web browser?
If you are using an unsecure web browser you will see a warning popup. The following web browsers are considered secure enough for file transfers:
  • Mozilla Firefox
  • Google Chrome
  • Opera
  • Microsoft Edge (usage of this web browser is discouraged)

We strongly disadvise the usage of the following web browsers:
  • Internet Explorer
  • Safari
Can third parties, such as employers and authorities, intercept files and read them?
Third parties can not read intercepted files because of the encryption process. However, they can intercept encrypted files if you are not connected to this website via a secure HTTPS connection or if the third party has installed monitoring software or spyware on your computer.

When you visit this website in a secure web browser files will be encrypted before being uploaded. This makes interception of files pointless.
What information is stored?
We store file names, file sizes, encrypted file contents, pseudorandom initialization vectors for encryption, pseudorandom password salts for cryptography, e-mail addresses of recipients and registered users and IP addresses to make this service work and to prevent abuse such as spam or violations of our terms of service.
How does the encryption process work?
For encryption of files we use the Advanced Encryption Standard (AES) algorithm with a key length of 128 bits. In addition, we make use of the PBKDF2 algorithm to derive encryption keys from entered passwords.

When you visit this website in a secure web browser the encryption process will take place locally on your own computer. You do not have to take additional steps to encrypt files.
Can third parties, such as employers and authorities, force me to hand over passwords or decryption keys?
In countries where privacy is under pressure, such as the United States, Russia, Iran, Turkey and China, authorities may force you to hand over passwords or decryption keys.