Put an AES-256 password on a zip, or remove one you know
Processed in your browser. Nothing is uploaded. Updated on 24 Oct 2026.A password on a zip keeps its contents private in transit, and AES-256 is what makes that real rather than decorative. Add one, or remove one you already know. Archives up to 2048 MB and 1,000 files, handled entirely inside your browser.
Leave What to do on Protect a zip, then press Select files or a zip, or drop files, a folder or a zip in.
Type a Password and repeat it in Confirm password; a lost password cannot be recovered.
Pick a Compression level and press Protect to build an AES-256 zip on your device.
Press Download to save the protected zip, and send the password separately.
Protect ZIP puts a password on a zip. Add loose files, a whole folder or an existing zip, choose a password, and download a zip whose contents are encrypted with AES-256, the strongest encryption the zip format supports. Unlock ZIP does the reverse for a zip whose password you know: you get the same files back in a zip that opens without one.
People protect a zip before emailing payslips, bank statements or client records, and before copying a folder to a shared drive or a USB stick. Unlocking is useful when a bank or a colleague sends a protected zip and you want to open it with the zip tool built into your computer, or keep it in a place where typing the password every time is a nuisance.
Both directions run in your browser; the files and the password stay on your device and nothing is uploaded. An existing zip is unpacked and packed again with the password, so you get one zip rather than a zip inside a zip. Zips that declare an absurd expanded size are refused before opening, as possible zip bombs. Up to 1,000 files and 2 GB.
Two honest limits. First, a zip keeps its file names and sizes visible; only the contents are encrypted, so use Encrypt File when the names themselves are private. Second, AES zips open in 7-Zip, WinRAR, WinZip, PeaZip, Keka and most phone file managers, but not in the zip tool built into Windows Explorer or macOS Archive Utility. Unlock ZIP cannot open a zip whose password you do not know, and it never tries to guess one.
Choose Protect, add your files, a folder or an existing zip, type a password of at least 8 characters, confirm it, and click Protect. The download is a zip encrypted with AES-256 that asks for the password when opened. No signup, no upload, no watermark.
No. Unlock ZIP only works with a password you already know. It does not crack, guess or bypass passwords and never tries. If the password is lost, ask the person who made the zip to send the files again.
No. The zip is read, encrypted or decrypted by code running in your browser on your own device. The files and the password never leave it, and the password is discarded when the job ends.
The zip tool built into Windows Explorer and macOS Archive Utility only understand the old ZipCrypto scheme, which is easy to break. AES-256 zips need 7-Zip or PeaZip on Windows, Keka on macOS, or most file managers on Android and iPhone. Or unlock it here with the password.
No. In the zip format, file names and sizes stay readable; only the contents are encrypted. If the names themselves are sensitive, use Encrypt File, which hides the name inside an encrypted .enc file, or give the files neutral names before zipping.
Up to 1,000 files and 2 GB per zip, with passwords from 8 to 256 characters. Unlock opens zips protected with AES or the older ZipCrypto scheme; certificate-based encryption is not supported. Large jobs need a desktop browser with free memory.
Still stuck? Ask about Protect ZIP / Unlock ZIP and anybody who knows can answer. No account needed.
Same job, other tools: Decrypt File – Open a .enc file encrypted here, with its password.
On the related tools: JPG to PDF – Convert JPG photos into a single PDF, in the order you choose.
Also works as: Password Protect ZIP.
In the collection Privacy and Protection Tools.