Why does my PDF have so many nearly-empty pages?

A forty-page document with about eight pages of content in it is common. Templates do this when nobody checks.

The four usual causes

Section breaks. Most report templates start each chapter on a new page, and many start it on a new *odd* page. That is a habit from double-sided printing, and it adds a blank sheet whenever a chapter ends on an odd page. It makes sense for a bound book, but not for a document people only read on a screen.

Keep-with-next and table protection. A word processor will not split a table across pages if it can avoid it, and will not leave a heading stranded at the bottom of a page. Both rules push content down. A table that is one line too long for the space left moves entirely to the next page, leaving most of the previous one empty.

Fixed-height elements. An image sized to "fill the width" of a page in a portrait document can be tall enough that nothing else fits beside it. Charts exported at a fixed size do the same.

Explicit page breaks nobody removed. Someone inserted them while drafting to make a section start where they wanted, then the text around it changed and the breaks stayed.

How to see how bad it is

Open the PDF and look at the page thumbnails rather than the pages. Whitespace is obvious at that size in a way it is not when you are reading.

Or measure it: run the document through SmartShrink, which reports how much of each sheet contains ink before it changes anything. If most pages are under half full, the problem is the layout. The content is fine.

Fixing it at the source

If you still have the original file, fix it there:

• Turn off "start on odd page" unless the document is going to be bound.
• Allow tables to split, or set the rule to keep only the header row with the table.
• Remove manual page breaks and let the flow decide.
• Check images that are sized as a fraction of the page rather than in real units.

This is the better fix, because the next export will be right too.

Fixing it in the PDF you already have

Often you don't have the original. It came from someone else, or a system you don't control made it. Then you have to fix the PDF itself.

SmartShrink measures the content on each page and stacks sparse pages that sit next to each other onto single sheets at full size. Pages that are already full are left alone. The output is a shorter document with the same text at the same size.

There are two things it won't do. It won't shrink a dense page to make the total look better, and it won't combine pages that have links or form fields, because those would stop working.

What this is not

It is not compression. If the file is too heavy to email, the page count doesn't matter and Compress PDF is the tool. See the comparison.