What is a 7Z file?
7Z — high-compression archive
Use the format 7Z
A concrete example
Prepare a ZIP from a 7Z archive for a recipient without a suitable player.
Useful checks
Check the integrity of extracted files and the preservation of folders. An encrypted archive requires compatible handling.
Choose a conversion
Keep the original and open the result in the software or on the device that will need to use it.
Your questions about this format
Why did I receive a TAR.GZ file?
Gzip compresses a stream, while TAR groups the files of a folder. The engine therefore combines the two to preserve the contents of a multi-part archive. Open the TAR.GZ with compatible software, then check the extracted files.
Does converting an archive change the documents inside?
The goal is to change their container, not to convert each document. A PDF in an archive remains a PDF. To change its format, extract it and then use the Documents theme.
Will a ZIP archive necessarily be smaller?
No. JPEG photos, videos, or already compressed archives may shrink very little. Compare the size and prioritize especially the format that your recipient knows how to open.
What to do with a protected or damaged archive?
The form does not ask for a password. Unlock your archive locally if you are allowed to, then try again with a copy. If it is damaged, first check that your local software can extract the files; paying does not repair an unreadable archive.
What is it?
The 7Z format compresses harder than any mainstream alternative: on a typical set of documents, it routinely produces archives 30% smaller than a ZIP.
This efficiency comes down to two things: a more sophisticated algorithm, and above all the "solid" mode, which treats every file as a single continuous block. This lets it exploit redundancy across files, something ZIP simply ignores.
History & origin
Igor Pavlov released 7Z along with its companion program 7-Zip in 1999, free and open-source, built around an algorithm of his own design.
Its quality earned it a reach well beyond the original software: it now shows up in countless installer systems and professional tools.
Why it is useful
It offers the best compression ratio among mainstream formats, genuinely strong AES 256-bit encryption, and no size limit.
It's free and open-source, and it can also open most other archive formats.
Limits & drawbacks
Neither Windows nor macOS supports it natively, so whoever receives your file will need to install extra software.
Solid mode has a downside: extracting a single file means decompressing the entire block it belongs to.
Practical tips
7Z is ideal for your own backups, where every megabyte counts.
When sending a folder to someone else, convert it to ZIP instead: you'll lose a bit of compression, but you'll be sure it opens without a hitch.
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Convert a 7Z