Free tool
Lock a file before it leaves your hands
Seal any file with a password and send the sealed copy by email, chat, or a USB stick. Encryption and decryption both happen in this page, so the file is never uploaded.
Encrypt
Seal a file
Any file type. Large files take longer because the work happens on your device.
Sealed file ready
Send the sealed file and give the password to the recipient through a different channel.
Decrypt
Open a sealed file
Choose a file that was sealed on this page.
File recovered
What the password protects
The file is encrypted in this page with a key derived from your password. The sealed result is the only thing that leaves your device, so a mail provider, a chat service, or a courier sees a file it cannot read.
There is no recovery
The password is not stored, not transmitted, and not escrowed. If it is lost, the sealed file cannot be opened by us or by anyone else. Keep it in a password manager, and test the round trip once before you delete the original.
What encryption does not hide
The sealed file still shows its size and the time it was created, and the channel you send it through sees that a file was sent. Encryption protects the contents, not the fact that you sent something.
Is the file uploaded at any point?
No. The file is read by the page, encrypted on your device, and handed back to you as a download. There is no upload step in either direction.
Can I open the sealed file with another tool?
Use this page. The container format is specific to this tool, so other programs will not recognise it. That also means you should keep the tool available for as long as you keep the sealed file.
How large a file can I encrypt?
The limit is your device's memory, not a server rule. Files of a few hundred megabytes work on a desktop but can be slow on a phone, and the tab has to stay open until the download starts.