Free PDF Compressor
Shrink PDF file sizes to meet KDP's upload limits — lossless optimization or aggressive image compression, all in your browser.
Compression Setup
Image modes re-render each page as a picture: text becomes non-selectable and print sharpness drops. For KDP print interiors, prefer Lossless Optimize.
Select a PDF and a compression mode. Results appear here with before/after sizes.
KDP's manuscript upload limit is 650 MB, but files under 400 MB convert much faster. Large files are usually caused by high-resolution images — for print interiors, 300 DPI is all you need.
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Frequently Asked Questions
Is my PDF uploaded to a server?
No — compression runs entirely in your browser; your file never leaves your device.
Which mode should I use for a KDP print interior?
Use Lossless Optimize — it keeps your text sharp and selectable. The image-based modes rasterize every page, which hurts print quality and removes selectable text.
Why didn't my file get smaller?
Some PDFs are already well-optimized (for example, exported cleanly from InDesign) — try an image compression mode for further reduction, understanding it will rasterize the pages.