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Compress PDF

Reduce PDF file size.

🔒 Runs entirely in your browser — nothing here is ever uploaded

About the Compress PDF

Shrinks a PDF's file size by restructuring it and removing redundant internal objects, entirely in your browser.

How to use it
  1. Upload a PDF.
  2. Click Compress & download.
  3. Check the before/after size in the result panel.
Formula
Uses pdf-lib to re-save the PDF with deduplicated internal objects and object streams — a structural optimization, not image recompression.
Worked example

An unoptimized PDF with duplicated fonts or resources can shrink noticeably; a PDF that's already well-optimized or dominated by large embedded photos will shrink only slightly.

Recommendations
  • • This works best on PDFs exported by older or less-optimized tools — results vary a lot by source PDF.
  • • For an image-heavy PDF that needs real size reduction, compressing the images before building the PDF (see the Image Compressor) will do more than this tool alone.
  • • Always check the reported size change — a small or zero reduction on an already-optimized file is expected, not a bug.
Frequently asked questions
It depends entirely on the source PDF — files with redundant or unoptimized internal structure shrink the most; already-compact, image-heavy PDFs may see little change.
Related tools
Merge PDF
Image Compressor
Sources