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Reduce file size while preserving quality — no upload
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Your files stay on your device · 0 uploads
PRIVATE PDF TOOL
Compress PDF
Reduce file size while preserving quality — all in your browser.
100% client-sideNo server involved
No uploadsYour files stay private
No account neededStart merging instantly
How it works
Merge your PDFs in just a few clicks.
1. Upload your PDF
Select the PDF you want to reduce in size.
2. Choose compression level
Pick between light (quality preserved) or aggressive (maximum size reduction).
3. Compress
Processing runs instantly in your browser — no upload wait.
4. Download
Save your smaller PDF file, ready for email or web sharing.
Your files never leave your device.
WhisperDocs runs entirely in your browser. All processing happens locally on your device, with no uploads, no accounts, and no tracking. Ever.
Processed in your browser
100% private
You stay in control
Common questions
Everything you need to know about merging PDF files with Compress PDF.
Compression results vary by content. PDFs with many images typically see 50-80% reduction. Text-heavy PDFs compress less.
You can choose compression level — light compression preserves full quality; aggressive compression reduces image resolution for maximum size reduction.
No. Compression runs entirely in your browser. Your file stays on your device throughout the process.
You will need to provide the password to open the file first. Once unlocked, compression works normally.