PDF compression guide
Lossless PDF compression is possible for some files, but not every PDF can become much smaller without some trade-off. The key is to use the largest accepted target and check the result.
Text instructions, duplicate objects and unused data can often be optimised with little visible change. Large images and scans usually require quality or resolution changes to save meaningful space.
Choose 2MB or 1MB before trying 500KB or smaller. Over-compression can make scans soft, photos blocky and small text harder to read.
If quality matters, start with a clean source: remove duplicate pages, crop unnecessary margins and scan at a sensible resolution before making the PDF.
Check original and compressed versions side by side. If important details are worse, use a larger target or adjust the source document instead.
No. Some PDFs can be optimised without visible loss, but large scans and photos usually need lossy image compression to become much smaller.
The largest target accepted by your portal or recipient usually keeps the best quality.