Password-protect ZIP
Lock files in a ZIP with a password, with AES-256 encryption. Done on your device.
How to use it
- Add the files or a folder, or choose “A ZIP I already have” and add that ZIP.
- Type the password twice and pick the encryption.
- Press the button and download the locked ZIP. Send the password by a different route than the file.
Questions
How strong is it?
AES-256 in the WinZip format, with the key made from your password by PBKDF2. The strength depends on the password: a short or common one can be guessed whatever the method. Use a long passphrase or one from the password generator.
Which programs open it?
AES-encrypted ZIPs open in 7-Zip, WinZip, PeaZip, Keka and The Unarchiver. Some built-in tools, such as the file browsers of older Windows and the macOS Archive Utility, may not open AES. If the other person only has those, choose ZipCrypto, which nearly everything opens.
What is wrong with ZipCrypto?
It is the original ZIP encryption and it is weak: it can be broken quickly by an attacker who knows some of what is inside. Use it only when compatibility matters more than secrecy.
Are the file names hidden?
No. A ZIP shows names, sizes and dates to anyone, without the password. Only the contents are locked. If the names are private too, use Encrypt / decrypt files, which hides the name, or put everything into one file first.
What if I forget the password?
The files cannot be recovered by anyone, including us. Nothing is stored and nothing is sent anywhere.
Can I lock a ZIP I already have?
Yes. Choose “A ZIP I already have”, add it, and it is opened and packed again with the password. If the ZIP already has a password, open it with Extract ZIP first.
Are my files uploaded anywhere?
No. This tool runs in your browser, so your files stay on your device and are never sent to a server.
Is it free?
Yes, you can use it for free. A subscription removes limits and unlocks premium tools.