How to reduce PDF size without losing quality
The short version: for scanned or photo-heavy PDFs, Compress PDF at the Balanced setting gets a large reduction with no visible loss. For text PDFs there's little to compress without turning the text into an image — so the honest answer is "compress the images inside it, not the whole file."
Compress PDF
Reduce PDF file size by rendering pages as compressed images.
Two definitions of "quality"
- A scan or photo PDF: the "quality" that matters is how the page *looks*. Re-encoding the images at 70–85% JPEG quality is visually the same at normal zoom but a fraction of the size.
- A text PDF: the "quality" that matters is that text stays selectable, searchable and crisp at any zoom. Any tool that dramatically shrinks a text PDF has almost certainly rasterised it — which technically loses that quality even though the page looks identical at first.
The safe approach
- Scan / photo PDF: run it through Compress PDF at Balanced. Check the before/after figure and the result. Done.
- Text PDF with images: don't compress the whole file. Compress each image with Compress Image first, then assemble the PDF. The text pages stay untouched.
- Text-only PDF: it's already about as small as it gets. If it's still "too big", the problem is usually the page count, not the compression — split it or send fewer pages.
Why the number matters less than you think
A 2 MB text report is not a problem to email or upload almost anywhere. Before spending effort compressing, check whether you actually need to — see why is my PDF so big.
Do it now
Open Compress PDF for a scan, or Compress Image for the pictures inside a text document.
Frequently asked questions
- Is lossless PDF compression a real thing?
- Truly lossless shrinking (removing duplicate objects, subsetting fonts, re-packing streams) exists but usually only saves a little, and needs a server-side pipeline. Big reductions always come from re-compressing images, which is lossy.
- How do I keep text selectable?
- Don't run a text PDF through an image-based compressor. Instead, compress the images inside it individually before you build the PDF, and leave the text pages alone.
- What quality setting is 'safe'?
- For scans and photos, the Balanced setting is usually indistinguishable from the original at normal viewing size. Only drop to Smallest when you've checked the result and it's acceptable.
Related guides
- How to compress a PDF without wrecking it
What actually makes PDFs large, why some compressors do more damage than others, and how to pick the right approach for your file.
- Why is my PDF so big? (and what to do about it)
PDFs balloon for a small number of reasons — scanned pages, embedded photos, fonts. Here's how to tell which one is yours and fix it.
- How to convert images to PDF (JPG, PNG, phone photos)
Turn one or several JPG or PNG images into a single PDF, in the right page order — what the tool does, the steps, and the common snags.
Compress PDF
Reduce PDF file size by rendering pages as compressed images.