Adobe Acrobat - Split pdf generates each files almost same size as the original pdf

I'm trying to transfer the Lumberyard's user guide into my Kindle Paperwhite. Unfortunately, this user guide is too large for my Kindle: 2680 pages - About 90MB.

So I try using the Split feature of Adobe Acrobat to split the guide into chapter:

But how ridiculous, Each of the split files (XXX_Part1.pdf, XXX_Part2.pdf,...) has size about 80MB (almost same as the original PDF - 90MB),

80MB - Each!!!

Even the first file (XXX_Part1.pdf) only has 2 pages, but the size is still ~80MB.

This is clearly unacceptable, how can I fix this? How can I create smaller split files?

Solution 1:

You can fix this with 2 step:

Step 1: Reduce the Original PDF's size. After it completes, you should have the reduced size PDF file

Step 2: Use the Split feature to split the reduced size PDF file. Wait and see your problem is solved.

Solution 2:

A solution I use for PDF splitting is a free tool called pdfsam.

The "basic" version is free and appears to do exactly what you are after.

Running it in "split mode" you can choose the number pages to split on. If I split on every page I get a lot (2500) of approximately 100-200kilobyte files. Splitting every 500 pages gets 5 nice 12MB to 25MB files.

There is also a "split by bookmarks" function which I initially overlooked. It split your file into 41 files with sizes ranging from 50KB to 13MB. You can find this tool on the main menu but be aware that it took about 30 seconds on my machine before it listed "levels" of bookmarks to export. There we no inexplicably large files.

Each tool in PDFSAM has an "advanced options" section. If I uncheck "compress output files" then the total output appears to be a nearly identical size to the input.

It definitely doesn't seem to suffer your problem of every file being approximately 80MB.