How to Compress a PDF Without Losing Quality
Some PDF compression is genuinely lossless and some is not. Here is exactly which operations change your document and which cannot possibly.
7 min read
PDF Size, Compression and Conversion Guides
A PDF that will not attach to an email is almost always large for one of three reasons: scanned pages stored as full-resolution images, embedded fonts, or images inserted at print resolution into a document meant for screens. Knowing which one applies tells you exactly how to shrink it — and how much quality you will lose.
PDF guides(4)
How to Compress a Scanned PDF
A scan is a stack of photographs, so ordinary PDF compression barely helps. Downsampling to 150 DPI and greyscale typically cuts 80–95%.
8 min read
Why Is My PDF File So Large?
Divide the file size by the page count and the cause becomes obvious — scanned images, print-resolution graphics or embedded fonts each need a different fix.
7 min read
How to Reduce PDF File Size Without Losing Quality
Find out why your PDF is large — scanned pages, embedded fonts or print-resolution images — then pick the compression method that fits your platform.
8 min read
Topics in PDF
PDF questions
Why is my PDF so large when it is only a few pages?
Almost always scanned images. A page scanned at 600 DPI in colour is several megabytes on its own, and a scanner saves every page that way regardless of whether the content is a photograph or plain text.
Does compressing a PDF reduce its quality?
It depends on what is compressed. Downsampling images loses detail permanently. Removing duplicate embedded fonts and unused objects is lossless and often saves a surprising amount.
What size should a PDF be for email?
Keep attachments under 10MB to be safe. Gmail allows 25MB, many corporate mail servers cap at 10MB, and some at 5MB.