How to make a PDF smaller while keeping it readable

Choose a compression setting, understand why some files do not shrink, and check the parts of a document most likely to lose detail.

Updated October 4, 2026

Find out what makes the file large

A short PDF can be large when it contains high-resolution scans or photographs. A long report can be small when it contains mostly text. Compression works differently for these sources. FolioSprint reduces embedded image size and optimizes content streams, so image-heavy documents often have more room to shrink.

Start with balanced compression

Balanced is a useful first pass for mixed documents. Download the result and compare the size with the original. If you still need a smaller file, try the smaller-file setting and check the pictures and scans again. Reducing image quality is a tradeoff, not a way to add information that was missing from the original.

Text that belongs to a scanned image can become harder to read when that image is reduced. Pay particular attention to small print, thin chart lines, signatures, stamps and low-contrast areas. A zoomed-out thumbnail is not enough to judge readability.

Remove content you do not need

Blank scans, repeated pages and unrelated appendices can make an attachment unnecessarily large. If they are not needed by the recipient, remove them before compressing. This also makes the final document easier to navigate. Keep a complete original for your own records.

Why compression sometimes makes little difference

A text-only PDF or an already optimized scan may not shrink. Rewriting a PDF can even produce a slightly larger result. FolioSprint reports the actual change instead of promising a fixed percentage. A target such as “under 2 MB” may require fewer pages or a lower-resolution original.

Finish with a reading check

Open the output in the PDF reader your recipient is likely to use. Confirm that all pages are present, text is legible and the file meets the delivery limit. Send the compressed copy and retain the original when you might need higher-quality images later.