Zip & Unzip Files Online

How to zip files online (free)

1. Stay on the Create ZIP tab and drop your files — or whole folders — onto the box above.
2. Review the list: remove or rename files, use + New folder to organise them, and drag files onto a folder to move them into it. Pick a format and compression level if the defaults (ZIP, Normal) are not what you want.
3. Give the archive a name, add a password if you need one, and click Create ZIP. Save the file when it is ready.

Create folders inside your ZIP

Click + New folder to add a folder to the archive, then drag files onto it (or use its + add files button) to place them inside. You can also drop an entire folder from your computer onto the box — its structure is kept as it is in the resulting archive. Files can be renamed in the list before you pack them.

ZIP, 7z or TAR: formats and compression levels

The Format menu offers ZIP, 7z, TAR.GZ, TAR.XZ, TAR.BZ2 and uncompressed TAR. ZIP is the one everybody can open. 7z usually gives smaller files. The TAR formats are what Linux tooling expects. There are four compression levels: Store, Fast, Normal and Maximum.

ZIP archives are written to disk as they are built, so their size is not tied to your RAM. 7z and the compressed TAR formats run single-threaded in the browser and are noticeably slower than a desktop app; Maximum on a large input is slow and memory-hungry. Empty folders are only kept in ZIP output. RAR archives cannot be created. There are dedicated pages for creating a 7z and creating a .tar.gz.

Password-protect a ZIP with AES-256

Type a password into the optional password box on the Create tab and the archive is encrypted with AES-256. Encryption runs in your browser, so the password is never uploaded or stored anywhere. The resulting .zip opens right here (you’ll be prompted for the password) and in archivers that understand AES ZIPs, such as 7-Zip.

Windows Explorer cannot open AES-encrypted ZIPs. If the recipient will only use Explorer, tick the Windows Explorer compatible encryption option to use legacy ZipCrypto instead — but know that it is much weaker than AES-256. With the 7z format, the password also uses AES-256 and you can encrypt the file names as well. TAR formats cannot be encrypted.

Keep your password safe: there is no recovery. If you lose it, the contents cannot be decrypted — by us or anyone else.

Split a large archive into parts

Use Split to cut the archive into pieces of 10 MB, 25 MB, 100 MB, 700 MB, 2 GB, 4 GB (for FAT32 drives) or a custom size. The parts are named archive.zip.001, .002 and so on, the same raw volumes 7-Zip produces. To put them back together, open the first part with 7-Zip, join them with cat or copy /b, or drop all the parts into the join tool.

Edit an existing ZIP

Click Edit an existing ZIP to open an archive, then remove files, rename or move them, add new ones and save. Files you leave untouched are copied as they are, without being decompressed and recompressed, so editing a large ZIP is fast. You always download a new file; the original on your disk is not modified. The ZIP editor page explains the details, including what is possible with password-protected ZIPs.

Remove hidden Mac files from a ZIP (__MACOSX, .DS_Store)

ZIPs made on a Mac often carry invisible extras — __MACOSX folders, .DS_Store files and ._* resource forks — that confuse Windows users and bloat the archive. With Strip hidden system files enabled (it’s on by default), this tool leaves all of that out, along with Windows junk like Thumbs.db and desktop.ini. To clean a ZIP someone else made, open it with Edit an existing ZIP and save it again.

How to unzip / extract a ZIP file

1. Switch to the Extract ZIP tab and drop your .zip onto the box.
2. Browse the folder tree, search, and click a file to preview it — images, text, code, PDF, audio and video.
3. Download one file, a ticked selection, or everything. In Chrome and Edge you can also save to a folder.

The Extract tab is the full archive browser. It asks for the password when a ZIP is encrypted (ZipCrypto or AES-256), can test the archive for damaged files, salvages the files it can still find in a truncated ZIP whose directory is missing, and hides __MACOSX and .DS_Store clutter by default. To change what is inside, click Edit this ZIP in the toolbar: the open archive moves to the Create tab, where you can add, remove, rename or move files and save it again. If file names from a Japanese, Chinese, Korean or Cyrillic system come out scrambled, the filename encoding dropdown lets you pick the right encoding with a live preview.

Why katlab’s zip tool is different

Most “online zip” sites upload your files to their servers to process them. This one doesn’t. Everything — compression, encryption, extraction — happens inside your browser tab using JavaScript and WebAssembly. Your files never touch the network, so there’s nothing to leak, cache, or delete later.

Frequently asked questions

Are my files uploaded to a server?

No. Everything runs locally in your browser with WebAssembly. Your files never leave your device, and the page keeps working offline once it has loaded.

Is there a file size or count limit?

There is no fixed limit. ZIP archives are streamed to disk while they are created, and extracted files go to your browser’s temporary storage, so the practical limit is free disk space, not memory. Creating 7z and compressed TAR archives is slower, and Maximum compression on large inputs needs a lot of memory.

Do I need an account?

No. There is no sign-up, no account, and no tracking. The tool is free to use.

Can I create folders inside the ZIP?

Yes. Use the New folder button to add folders and drag files into them, or drop an entire folder from your computer — its structure is preserved in the archive.

Can I password-protect a ZIP file?

Yes. Type a password in the optional password box before creating the archive and it is encrypted with AES-256. The encryption happens in your browser, so the password never leaves your device. Windows Explorer cannot open AES ZIPs; for that case there is an optional legacy ZipCrypto mode, which is much weaker. Leave the box blank for a normal, unencrypted ZIP.

Can I create a 7z or tar.gz instead of a ZIP?

Yes. The Format menu on the Create tab offers ZIP, 7z, TAR.GZ, TAR.XZ, TAR.BZ2 and TAR. RAR cannot be created, because the format is proprietary.

Can I change a ZIP without extracting it?

Yes. Edit an existing ZIP opens the archive so you can remove, rename, move and add files, then save a new ZIP. Untouched files are copied without recompression, and the original file is not modified.

Does it remove hidden Mac files like __MACOSX and .DS_Store?

Yes. By default the tool strips macOS junk (__MACOSX folders, .DS_Store, ._* resource forks) and Windows junk (Thumbs.db, desktop.ini) when creating or editing a ZIP, and hides them when you open one on the Extract tab.

What formats can it open?

The Extract tab opens .zip files, including ZIP-based ones such as .apk and .jar, and other archive formats too: .rar, .7z, .tar.gz, .iso and more. The archive extractor page has the full list.