How to Create a Password-Protected ZIP File (AES-256)

Sending several documents at once is easier as a single ZIP file, and adding a password means only the people you trust can open the contents. It's a simple way to protect tax papers, scans of IDs or client files when you email them or put them on a USB stick.

Create a ZIP

1. Open Create ZIP Files.
2. Add files, or whole folders.
3. Optionally set a password for AES-256 encryption.
4. Download the ZIP.

You can also create a TAR.GZ archive, common on Linux and servers. There are no server-imposed limits on size or number of files; the ZIP is built in your browser's memory, so your device's free memory is the practical limit. The result is a standard ZIP that Windows, macOS, Linux, Android and iOS can open.

Password-protect files or an existing ZIP

Password Protect ZIP is dedicated to encryption: add files, folders or an existing ZIP, choose the encryption, enter a password and download the protected ZIP.

AES-256 or ZipCrypto?

• AES-256 is modern, strong encryption. With a good password, it can't realistically be broken. To open it, the recipient needs an archive app such as 7-Zip, WinRAR, Keka or The Unarchiver; the built-in ZIP support in Windows and macOS may not open AES-encrypted ZIPs.
• ZipCrypto is the old ZIP encryption. Windows and macOS open it without extra software, but it's weak and can be broken with known techniques. Use it only for low-sensitivity files when convenience matters more.

For anything confidential, choose AES-256 and tell the recipient which app to use.

Choose a strong password

Encryption is only as strong as the password. Short or common passwords can be guessed by software quickly.

• Use at least 12 characters, or a passphrase of several random words.
• Don't reuse a password from an account.
• Generate one with the Password Generator, which uses your browser's cryptographic random generator.

Send the password separately

If you email the ZIP and the password together, anyone who gets the email gets both. Send the password another way: a text message, a phone call, or a messaging app.

What a ZIP password doesn't hide

In a password-protected ZIP, the contents of files are encrypted, but the file names and sizes inside are usually still visible to anyone who opens the archive's list. If file names are themselves sensitive (passport-scan-john-smith.jpg), either rename the files before zipping, or zip them first and then put that ZIP inside a second protected ZIP.

Removing the password later

To get the same files without a password, use Unlock ZIP: type the password once and download an unprotected ZIP. Without the password, there's no way back; keep it in a password manager.

Common questions

Can I protect a single file? Yes. A ZIP can contain one file.

Does zipping make files smaller? Text, documents and spreadsheets often shrink a lot. Photos, videos and PDFs are already compressed and barely change.

Is my password sent anywhere? No. The ZIP is encrypted on your device; neither the files nor the password leave your browser.

Summary

• Create ZIPs of files and folders; add AES-256 for real protection.
• Use a long, unique password and send it separately.
• File names inside remain visible; rename sensitive ones.