It might sound weird but after months of making videos for my YouTube channel, I could tell which open source license a program is licensed under, just by looking at the file size of COPYING or LICENSE almost every single time. Is it GPL? If so, which version it is.

I just realized that I might be having a sense of GNU licenses’ file sizes, so here is a post for that and the sizes:

34,520 agpl-3.0.txt

18,138  fdl-1.1.txt
20,431  fdl-1.2.txt
22,962  fdl-1.3.txt

12,632  gpl-1.0.txt
18,092  gpl-2.0.txt
35,147  gpl-3.0.txt

25,383 lgpl-2.0.txt
26,530 lgpl-2.1.txt
 7,651 lgpl-3.0.txt

I downloaded most of GNU’s licenses in plain text, even though I could onl tell the GPL ones. I could recognize MIT, BSD, and of course GNU’s, by head the content when file size isn’t enough. Sometimes, some strange open-source-like license would pop up, but I just couldn’t really find the name of license.