Why is this PDF so big, and how do I make it smaller?
A PDF is almost always large because of the images inside it: scanned pages, photos, or screenshots stored at print resolution. Text barely counts. To make the PDF smaller, reduce those images. FileMate does that from Finder: right-click the PDF, choose Compress PDF, and a smaller copy appears next to the original, with text, links and forms intact.
FileMate reduces the PDF on your Mac. Nothing is uploaded.
Make a PDF smaller with FileMate
- In Finder, right-click the PDF and choose FileMate › Compress PDF.
- FileMate saves Report compressed.pdf next to the original and shows how much smaller it is.
- Need more? Click Want a smaller file? in the result and try Stronger, which recompresses the images as JPEG. Text, links and forms still stay.
- For scans that still have to shrink, Maximum turns each page into a compact image.
What takes up the space in a PDF
| Content | Typical size | Can compression help? |
|---|---|---|
| Text | A few KB per page | Barely: text is already compact |
| Embedded fonts | 20 KB to 1 MB per font | A little; fonts must stay for the text to display |
| Vector drawings and charts | Small, unless extremely detailed | Rarely |
| Photos and screenshots | Hundreds of KB to several MB each | Yes, a lot |
| Scanned pages | 0.5 to 5 MB per page | Yes, a lot |
If you can see photos or scanned pages in the PDF, there is room to make it smaller. If it is 60 pages of plain text and it is already 400 KB, there isn’t much left to take out.
How to check what you’re dealing with
- Select text. Open the PDF in Preview and try to select a sentence. If you can’t, the pages are images: a scan, or a PDF made from photos. Those shrink the most.
- Look at the size per page. Select the file in Finder and press Command-I to see its size. More than about 500 KB per page usually means high-resolution images.
- Zoom in on a photo. If it stays sharp at 400%, it is stored at a much higher resolution than any screen or printer needs.
Three ways to reduce the images
- Lower their resolution. A scan made at 600 dpi has four times the pixels of the same scan at 300 dpi. Screens and ordinary printing don’t need more than about 150 to 225 dpi. FileMate’s Safe level reduces images drawn above that density.
- Store them as JPEG. Photos saved losslessly inside a PDF take far more space than JPEG. FileMate’s Stronger level recompresses images as JPEG, with some quality loss.
- Turn pages into images. For scanned documents, re-rendering every page as one JPEG at a sensible resolution gives the smallest files. That is FileMate’s Maximum level. It also means text can no longer be selected or searched, so FileMate warns you before running it.
What won’t make a PDF smaller
- Zipping it. Finder’s Compress makes a
.ziparchive. PDFs with images are already compressed internally, so a ZIP of a PDF is usually only a few percent smaller, and the recipient has to unzip it. - Printing to PDF again. “Print › Save as PDF” often keeps the images as they are, and it can drop links and form fields.
- Renaming or re-saving it. The content stays the same, so the size does too.
Is there a limit to how small a PDF can get?
Yes. Every level of compression trades detail for size. A PDF of 30 photos can’t become 200 KB without the photos becoming unrecognisable. If you have a hard upload limit, see how to get a PDF under 10 MB.
Get FileMate
Most large PDFs are large because of images. FileMate reduces them from Finder, keeps the text working at its first two levels, and never touches the original.
Normal price €9.99, now €4.99 incl. VAT
One payment, no subscription. macOS 14 Sonoma or later, Apple silicon or Intel.