Compress PDF Online
Real compression — images are resampled & optimized. No upload to servers. 100% in your browser.
Compression Level
Low
Near lossless
~20–40%
Medium
Balanced quality
~50–70%
High
Small file size
~70–85%
Maximum
Smallest possible
~85–95%
🎉
Compression Complete!
How it actually compresses
01
Render Each Page
PDF.js renders every page to a high-res canvas element.
02
Resample Images
Canvas is scaled down and exported as compressed JPEG.
03
Rebuild PDF
pdf-lib assembles a new PDF from the compressed pages.
04
Download Instantly
Your file never leaves your device. 100% private.
