Why Is My PDF So Large? (And How to Fix It)

If a PDF is surprisingly large, there's almost always a specific culprit. Knowing which one tells you exactly how to fix it.

High-resolution images

The most common cause. Photos and screenshots placed at full resolution, or scans at high DPI, dominate the file size. Downsampling them is the fix.

It's a scan

If the whole document is scanned, every page is an image — see our scanned-PDF guide for the specific approach.

Embedded fonts

Fully embedded fonts add weight. Subsetting (embedding only the used characters) helps, though this is usually a smaller factor than images.

Leftover junk

Old revisions, thumbnails, and metadata accumulate. Re-saving through an optimizer clears these out.