PDF Compressor — Free Online Tool
Shrink PDF file size by re-rendering pages at a lower quality. Works best for scanned or image-heavy PDFs.
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Click to select a PDF to compress
About PDF Compressor
The PDF Compressor shrinks bulky PDF files by re-rendering their pages at a quality level you control, all inside your browser. It is most effective on scanned documents and image-heavy PDFs that are too large to email or upload.
Since processing is fully client-side, your files never touch a server. You get smaller, easy-to-share PDFs for free without sacrificing your privacy.
How to Use PDF Compressor
- Click the upload area and select the PDF you want to compress.
- Drag the quality slider to balance file size against clarity.
- Click 'Compress & Download' to process the document.
- The compressed PDF downloads automatically with a size summary shown.
Key Features
Adjustable quality slider for size-to-clarity control
Best-in-class results for scanned and image-heavy PDFs
Live before-and-after size comparison
100% client-side processing - files never leave your device
No watermarks, signup, or file size limits
Frequently Asked Questions
How does PDF compression work here?
Each page is re-rendered as a JPEG image at the quality level you choose, then rebuilt into a new PDF. Lower quality produces a smaller file, which works best for scanned or image-heavy documents.
Will the text stay selectable after compression?
No. Because pages are converted to images during compression, text becomes part of the page image and is no longer selectable. This trade-off is what enables strong size reduction.
Are my files uploaded to a server?
No. Compression happens entirely in your browser using pdf.js and pdf-lib. Your PDF never leaves your device, keeping it completely private.
What quality setting should I choose?
Use a higher quality for documents you need to read clearly and a lower quality when small file size matters most. The slider lets you balance clarity against size.