Another test of the Neevia Tech online compression linked to in my previous post:
I have a directory called /legal/ comprised of sub-directories and files (108 files in 18 sub-directories, and 36 of those files are PDFs. I compressed only the 20 largest of those 36 PDF files). The screenshot below shows the exact same /legal/ directory, zipped, at two different points in time, the 8th of this month (5 days ago), and the 13th (today). No files were added or removed. The only difference is the compression, today, of 20 of the 36 pdf files within:
So, the more recent zip file has "shrunk" by 2.08 Mb. Consider, too, that only 20 of the 108 files were compressed, and that in creating the PDFs initially from LibreOffice, I used relatively conservative resolution (300 dpi) -- the majority of the 20 compressed PDFs contained scanned images. Not shabby, especially considering that this /legal/ directory of mine will likely continue growing over the next few months (years?) {custody/medical issues re: 2 children with ex-spouse
} Could add up to many Mb of saved space over a period of time...
I'm not specifically advocating this particular online compressor. Obviously it would be much more efficient to find a means of batch compressing PDFs with given settings.