Compress PDF: why some files barely shrink
Published
What PDF compression actually does, when it works best, and how to set expectations for image-heavy documents.
Compression rebuilds structure and can rewrite streams. Vector text usually compresses well; high-resolution scans may already be near their entropy limit.
Image-heavy PDFs
If pages are full-page photos, shrinking without visible loss is hard. You may need raster recompression outside a lightweight online tool, or accept modest gains.
Try a round trip
Save the file, inspect file size, and compare visually. If nothing changes much, the source was likely optimized already.
LovePDF compressor
Our compressor rebuilds the document for many typical office PDFs and returns a compact PDF you can evaluate quickly.
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