Compress PDF
- Files never leave your device
- Runs in your browser
- Free, no sign-up, no watermark
Drop PDFs here, or click to choose
Accepts PDF · You can also paste with Ctrl+V / ⌘V
How to use Compress PDF
Make PDFs smaller without uploading them. Photos that are stored at far more pixels than their size on the page needs are scaled down and re-saved as JPEG, duplicate images are merged, and the file is saved in a compact form. Text, fonts and vector graphics are left untouched, so text stays sharp and selectable.
- 1
Drop one or more PDFs on the page. If a file is password-protected, type its password on its row and click Unlock.
- 2
Pick a Compression level: Smallest, Balanced, or High quality. Choose Custom to set Max image resolution and JPEG quality yourself.
- 3
Click Compress PDF (or Compress N PDFs). Each row then shows the old and new size, how much smaller it is, and how many images were recompressed or skipped.
- 4
Download each file, or use Download all (ZIP).
Frequently asked questions
Are my files uploaded?
No. Compression runs in your browser, in a background worker, so your PDFs never leave your device. There is no limit on file size or the number of files beyond your device's memory. Our iLovePDF alternative page shows measured results.
How does it make the PDF smaller?
It works out how large each image is drawn on the page. Images with more pixels per inch than the chosen level allows are scaled down and saved as JPEG at the chosen quality; byte-identical copies of an image are stored once; unused objects are removed; and the file is saved with compressed object streams.
Which level should I choose?
Balanced (150 ppi) suits reading on screen and office printing. Smallest (100 ppi, lower JPEG quality) gives the smallest files for email. High quality (220 ppi) keeps photos sharp in print but saves less.
Why does it say Already optimized?
Text-only PDFs, scans stored as JBIG2 or fax images, and files whose images are already at a low resolution have little to remove. If the result is not at least 1% smaller, the original file is kept, so you never get a bigger file.
Which images are left untouched?
CMYK images, indexed and spot-color images, 1-bit and 16-bit images, JPEG 2000, JBIG2 and fax-compressed images, masks, and images stored inside the page content are kept exactly as they are. Each result lists how many were skipped and why.
Can I compress a password-protected PDF?
Yes, if you know the password. The compressed copy is saved without a password; use Protect PDF to add one again.
Are links, bookmarks and form fields kept?
Yes. Pages, text, links, bookmarks, form fields and annotations stay as they were. A digital signature, however, no longer validates, because the file's bytes change.