How does Windows decide whether to use Deflate or Deflate64 for zipping files?

user_4018042 0
Viewed 81

Windows Explorer uses the Deflate64 compression method for its zip files, rather than Deflate. Is this behaviour consistent across "current" Windows versions?

I tried one way. I created one zip file whose size is 2.69 GB, and one folder whose size is more than 1.23.

After zipping both of them, the zip file was created using Deflate64 and its size was 3.19 GB.

I would like to know how Windows decides whether to zip the file using Deflate64 or Deflate? What are the conditions required to create Deflate64 zip files?

operating-system deflate windows
1 Answers

See this note:

Windows 7/8/10 all use Deflate64. The cutoff in zip size where it switches from Deflate to Deflate64 appears to be 2 gigs. The number of files within the zip is irrelevant to the compression type chosen e.g. one 2.5 gig file will be Deflate64’ed the same as five 0.5 gig files.

user_11806200
Related