Compress PDF online
Reduce PDF size while keeping quality.
Compress PDF online (complete guide)
PDF compression is about trade-offs: smaller file size vs visual quality. For text-heavy PDFs (digital exports), you can usually compress aggressively with little visible change. For scanned PDFs (images of pages), compression can quickly make text blurry if you go too far. This guide helps you pick the right level and avoid common mistakes.
When to compress (and when not to)
- Compress when you need to send by email, upload to a portal with size limits, or improve download speed.
- Don’t re-compress a PDF that’s already optimized—multiple passes often degrade scans.
- Consider splitting with Split PDF if you only need a section.
Pick the right compression level
- Medium: best default for most documents; usually safe for readability.
- Low (smallest): for quick sharing when file size is critical; check for blur on small text.
- High (better quality): use when you still need a smaller file, but scans must remain crisp.
Best workflow for scanned PDFs
- Try Grayscale PDF first (often reduces size without damaging edges as much as aggressive compression).
- Then run Compress PDF on Medium.
- Spot-check: zoom to 100% and verify small text, signatures, stamps, and QR codes.
Reduce size without losing meaning
- Remove unnecessary pages with Remove pages (blank pages, duplicates, appendices you don’t need).
- Extract only what you share using Extract pages.
- Remove metadata with Remove metadata for privacy hygiene (doesn’t shrink much, but improves trust).
Privacy & retention
Files are stored temporarily for processing and deleted on scheduled cleanup (typically within 12 hours).
Troubleshooting
- Compressed file is larger: your PDF may already be optimized; try High (better quality) or keep original.
- Text becomes blurry: use High, or grayscale first; avoid repeated compressions.
- Images look blocky: compression is too strong; use High and avoid Low for image-heavy docs.
- Processing fails: split the PDF and compress parts separately.
How it works
- Upload a PDF.
- Choose compression level (Medium is recommended).
- Download the compressed PDF and spot-check readability.
FAQ
Will compression reduce quality?
It can. Medium is the safest default; scans may blur if you choose aggressive settings.
Which level should I choose?
Start with Medium. Use High if scans must stay crisp; use Low if size matters more than quality.
Why did my compressed file get bigger?
Some PDFs are already optimized. In that case, keep the original or try a different level.
How do I compress a scanned PDF safely?
Try Grayscale first, then Compress on Medium, and verify text at 100% zoom.
Can I reduce size by removing pages?
Yes — Remove pages or Extract pages often reduces size more than compression alone.
Does compression remove metadata?
Not reliably. Use Remove metadata if you want to clean document properties.
Will this change page order or content?
No. Compression only optimizes the file; it doesn’t rearrange pages.
Can I compress after merging PDFs?
Yes. A common workflow is Merge PDF → Compress PDF.
Can I compress password-protected PDFs?
Only after unlocking them (requires the password).
How long are my files stored?
Files are stored temporarily for processing and deleted on scheduled cleanup (typically within 12 hours).
Related tools
Privacy note: files are stored temporarily for processing and deleted on scheduled cleanup (typically within 12 hours).