Compress PDF
Reduce PDF file size.
Original size
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Compressed size
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Size reduction
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FAQ
- Is my PDF uploaded to a server?
- No. All processing happens entirely in your browser using pdf-lib. Your file never leaves your device.
- How much will my PDF shrink?
- Results vary. This tool restructures the PDF using object streams, which typically reduces size by 5-25% on unoptimized files. It does not re-encode or downsample images, so heavily image-based PDFs may see little change.
- Why is browser-side PDF compression limited?
- True aggressive compression (re-encoding images at lower quality, subsetting fonts, flattening layers) requires a full PDF rendering pipeline. Browser-based tools like this one primarily restructure the document, which helps for text-heavy and poorly-structured PDFs but cannot match desktop tools such as Acrobat or Ghostscript for image-heavy files.