Create a ZIP file
Files and folders packed into one ZIP on your own device, locked with a password when they are private.
- Nothing is uploaded
- Works offline after first visit
- Open source
- No watermark. A ZIP can be up to 4 GB, and phones hold less.
Zips files or whole folders into one ZIP and can lock it with an AES-256 password. It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. A ZIP can be up to 4 GB, and phones hold less; give the page a short while after one visit to save itself for offline use, and then it works offline.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
How it works
- Drop files or a folder, or press Add a folder.
- Tick Lock with a password and type one if the files are private.
- Press Create ZIP; the ZIP downloads straight away.
In your browser, not on a server
Your files are read into this tab and packed with fflate (MIT), which deflates text and documents and stores already-compressed photos, videos and archives as they are. Folders you drop or pick keep their structure inside the ZIP. With a password, each file gets its own random salt; PBKDF2 with SHA-1 (the browser’s Web Crypto) turns the password into an AES-256 key and an authentication key, the compressed file is encrypted with AES in counter mode (the AES code is @noble/ciphers, MIT, an audited JavaScript library), and an HMAC lets the opener check the password and spot tampering. This is the WinZip AE-2 format that 7-Zip and WinRAR write.
Compared with upload-based tools: Online zippers upload every file, and a password-protect service sees both the files and the password, which defeats the point of locking them. Here nothing leaves your device and there is no size cap beyond your device’s memory (phones hold less).
Verify it yourself. Give the page a short while after one visit to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
How strong is the password lock?
Each file is encrypted with AES-256 in the WinZip format, with a key made from your password and a random salt. That is the strong kind of ZIP encryption, not the old ZipCrypto scheme that tools can break in minutes. The lock is only as good as the password, so use a long one and send it separately from the ZIP.
Can everyone open a password-protected ZIP?
7-Zip, WinRAR, PeaZip, The Unarchiver, Keka and our own archive opener all can. The zip openers built into Windows and macOS may refuse AES-locked ZIPs, so tell the person you send it to which app to use. ZIPs without a password open everywhere.
Why are photos and videos barely smaller in the ZIP?
JPEG, PNG, MP4 and similar files are already compressed, so they are stored as they are rather than squeezed again, which saves time. Text, documents, spreadsheets and code usually shrink a lot.
Are my files uploaded?
No. The ZIP is built in this tab with fflate, and the encryption runs here too, so neither the files nor the password leave your device.
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