Files · Windows 10 and 11
Make a 7Z file
7Z usually packs tighter than ZIP, which makes it the format for backups and big uploads. Choose files and folders in Files, pick 7Z and press Compress to 7Z. With a password, the file names are locked too, not just their contents.
How to make a 7Z file
- 1
Choose files and folders
In Files, press Choose files… or A folder… under Compress, or drop them on that box. From File Explorer: right-click them, then Octoolo and Compress….
- 2
Choose 7Z
Pick 7Z under Format, then Fast, Normal or Smallest under Compression. Smallest takes longer and more memory.
- 3
Lock it, if you like
Turn on Add a password and type it twice.
- 4
Compress
Check the name under Save as (the .7z is added for you), press Compress to 7Z and watch the progress. Stop removes the unfinished file.
How the levels compare
| Level | LZMA2 preset | Dictionary | Threads |
|---|---|---|---|
| Fast | 1 | 1 MB | Up to 4 |
| Normal | 5 | 8 MB | Up to 4 |
| Smallest | 8 | 32 MB | Up to 2 |
A bigger dictionary finds repeats further apart, which pays off on large folders of similar files, such as documents, code or logs. It also needs more memory, about 370 MB per thread at Smallest, which is why that level uses two threads at most. Files are packed together in solid blocks of up to 1 GB, which is what makes 7Z smaller than a ZIP of the same files.
A password that hides the names
With Add a password on, the files are encrypted with AES-256, and so is the list of names. Without the password, nobody can see what the 7Z holds, not even the names, which a ZIP cannot hide (see password-protect a ZIP). There is no way to recover a lost password.
Who can open a 7Z
7-Zip, WinRAR, Octoolo and many other archivers open 7Z files, and so does File Explorer on Windows 11 since a 2023 update. Windows 10 and macOS need an app. When you are not sure what the other person has, a ZIP is the safer choice: see zip a folder.
Octoolo or an online tool?
| Detail | Octoolo | A typical online tool |
|---|---|---|
| Your files | Stay on your computer | Usually uploaded to the site's server |
| Without internet | Works | Does not work |
| File size | No limit | Often capped on free use |
| Watermarks and ads | None | Common on free plans |
| Cost | $4.99 a month, all 17 apps | Free with limits, or a plan per site |
Questions, answered
Is 7Z smaller than ZIP?
Usually, especially for text, documents and code, thanks to LZMA2 and solid blocks. For photos and videos, which are compressed already, the difference is small.
Can I split a 7Z into parts?
Not yet. Octoolo opens split 7Z files (.7z.001) but makes one file.
Can I stop it halfway?
Yes, press Stop: the unfinished 7Z is removed.
Can I make a RAR instead?
No. Only WinRAR can create RAR files.
Make a 7Z file, and 16 more apps.
Download for Windows7 days free, then from $3.99 a month for all 17 apps. Windows 10 and 11.