Is it possible to extract foreign zip files with 7zip without adding a region to your computer?
In my 3D modeling circle, many users download and extract zip files from Japanese or Chinese creators. Generally, we are taught to add the relevant regions to our computers to ensure safe text/filename extractions. Some of us use Bandizip to extract because it allows foreign zip-extraction without adding regions, but is this possible with 7zip too? Thanks!
Solution 1:
For .zip files, 7-zip does not have codepage autodetection. It fully understands Unicode-based .zip archives1, but if the filename wasn't stored as Unicode, then 7-zip will always use the current system's region codepage when extracting (and will result in garbage if the regions don't match). There seems to be no way to tell it to use something else.
If you do not like Bandizip, then WinRAR may work as an alternative – it does have an "Options → Name encoding" menu (at least in version 6.00) which can be used to manually specify the correct codepage, e.g. "932 Shift-JIS" for Japanese filenames.
For .7z and .rar files there should not be any problems, as those formats almost always use Unicode filenames, so their extraction should always work regardless of system region.
1 Unicode support in .zip archives is relatively new2; many older programs unaware of the new addition create .zip files with filenames stored in the system codepage. What's worse is that .zip archives have no indication as to which region's codepage is being used; the unarchiver is just expected to know (or guess).
I suspect that many of the problematic archives are those that were created through the Windows "Compressed Folders" feature. For a very long time it had no Unicode support at all; it would always create and extract archives using the current "region" codepage (e.g. Windows-1257 or Shift-JIS).
This did improve over time; according to my tests, Windows 10 version 1703 was able to extract (but not yet create) Unicode-based Zip archives, and Windows 10 version 21H1 is finally creating .zip files with Unicode (UTF-8) filenames.
(Still does it incorrectly and doesn't set the flag that would indicate that the name is indeed stored as UTF-8, but that's a minor issue that most unarchivers will just automatically correct.)
2 7-zip and WinRAR recognize all three methods for storing Unicode names in .zip archives (direct UTF-8; legacy Info-ZIP extra field; and direct UTF-8 with the "UTF-8" indication flag missing).