How to Create a ZIP or 7z Archive (and Which One to Choose)
Most archive problems start with the sender. A ZIP made with the wrong options, an AES password the recipient cannot open, or a 7z sent to someone without 7-Zip all create work at the other end. This guide shows how to create ZIP and 7z archives on each platform, which settings actually matter, and how to check the result before you send it.
Updated 2026-10-13 · Written and tested by the UnpackNest editorial team (TECCONET)
Choose the format first
| If the recipient… | Send | Reason |
|---|---|---|
| uses any device and is not technical | ZIP | Opens without extra software on Windows, macOS, iOS, Android and ChromeOS |
| needs the smallest possible download | 7z | LZMA2 usually beats ZIP, especially on text and code |
| needs strong encryption with hidden file names | 7z (AES-256) | Standard ZIP cannot hide names; AES ZIP needs extra tools anyway |
| works on Linux servers or with source code | .tar.gz | Keeps Unix permissions and is the norm there |
When in doubt, send a ZIP. A slightly larger file that opens everywhere beats a smaller one that needs a support call.
UnpackNest is a reader: its tools open and extract archives but do not create them. The steps below use your operating system or free desktop software.
Windows: create a ZIP
- Select the files or folder in File Explorer.
- Right-click and choose Compress to ZIP file (Windows 11) or Send to > Compressed (zipped) folder (Windows 10).
- Type a name for the new ZIP and press Enter.
Recent Windows 11 versions also offer Compress to… > Additional options, where you can choose 7z or TAR and a compression level. If you do not see it, update Windows or use 7-Zip.
Windows and Linux: create a ZIP or 7z with 7-Zip
- Right-click the files, choose 7-Zip > Add to archive… (on Windows 11, first Show more options).
- Set Archive format to
zipor7z. - Leave Compression level at Normal unless size matters a lot; Ultra is slower and gains little on photos and videos.
- For a password, type it under Encryption and choose AES-256. For 7z, tick Encrypt file names.
- To split a big archive, choose a size in Split to volumes, bytes, for example
2Gfor files that must fit on a FAT32 drive or under an upload limit. - Press OK.
On Linux the same command-line tool is available: 7zz a -tzip project.zip project/ for ZIP, or 7zz a -t7z -mhe=on -p project.7z project/ for an encrypted 7z with hidden names (it prompts for the password).
macOS
- Select the files in Finder.
- Right-click and choose Compress. macOS creates
Archive.zip, orname.zipfor a single item.
The built-in option cannot add passwords or create 7z. For those, use Keka: drag files onto the Keka window, choose 7z or ZIP, set a password if needed. In Terminal, zip -er secret.zip folder/ creates a password-protected ZIP, but it uses the weak ZipCrypto method; prefer Keka with AES-256 for anything sensitive.
macOS adds hidden __MACOSX folders and .DS_Store files to ZIPs. Windows users see them as clutter. Keka can exclude them; from Terminal, zip -r project.zip project -x "*.DS_Store" -x "__MACOSX/*".
Linux terminal
- ZIP a folder:
zip -r project.zip project/. - Tarball:
tar -czf project.tar.gz project/. - 7z:
7zz a project.7z project/.
Android and iPhone
- iPhone/iPad: in the Files app, select items, tap More (…) > Compress.
- Android: Files by Google cannot create archives on many phones; Samsung My Files can (More > Compress). Apps such as ZArchiver can create ZIP and 7z.
Settings that actually matter
- Compression level: "Normal" gets most of the benefit. Higher levels mainly cost time.
- Solid archive (7z): smaller output for many small files, but one damaged byte can affect several files. For backups you might need to restore partially, consider turning it off.
- Dictionary size (7z): bigger can mean smaller archives, but the recipient needs more memory to extract. Huge dictionaries can make archives impossible to open on phones or in browsers.
- File name encoding: modern 7-Zip writes UTF-8 names in ZIPs, so Arabic and other non-Latin names survive.
Do not compress what is already compressed
JPEG photos, MP4 videos, MP3 audio, PDF files and Office documents (.docx, .xlsx) are already compressed. Zipping them saves little, sometimes nothing. Archive them for convenience (one file instead of fifty), not for size. Text, CSV, logs, source code and uncompressed images (BMP, TIFF) compress very well.
Check the archive before you send it
- Test it: in 7-Zip choose Test; in a terminal
7zz t archive.7zorunzip -t archive.zip. - Open it in the tool your recipient will use. For a quick, private check of a ZIP or 7z, open it in the UnpackNest ZIP tool or 7z tool and confirm the file list and sizes.
- Make sure you did not include private files by accident: a whole Desktop folder, a
.gitfolder, or a configuration file with passwords.
Naming and sending
- Use plain names without spaces or special characters, for example
project-report-2026-10.zip. - For split archives, keep the generated names (
.7z.001,.7z.002or.zip.001) and send every part. - Include the password through a separate channel, and tell the recipient which tool opens the archive.
- For large archives, share the SHA-256 checksum so the recipient can verify the download.
Frequently asked questions
Is 7z always smaller than ZIP?
Usually, for text and code. For photos and videos the difference is tiny because they are already compressed.
Can I create a RAR file?
Only with WinRAR or the rar command-line tool, both commercial. For most purposes, ZIP or 7z is a better choice for the recipient.
Why can't my recipient open the ZIP I made on a Mac?
Usually an AES password (not supported by Windows Explorer) or non-ASCII names created by an old tool. Re-create it with Keka or 7-Zip.
Tools for this task
- Open and extract ZIP files in your browserStore, Deflate and ZIP64, read on your device.
- Open 7z files and split .7z.001 archives onlineLZMA/LZMA2, AES-256, multi-volume.