Compress PDF
Reduce PDF file size without losing quality
At a glance
- Use this page to compress files quickly with a guided workflow.
- Accepted input: .pdf.
- Output: downloadable file generated in-browser for supported workflows.
- Upload Choose your file
- Process Runs locally
- Download Save result
Drop your file here
or tap to browse · accepts .pdf
Runs in your browser. No file uploads for supported tools.
Best on desktop for 100MB+ files · mobile recommended under ~100MB.
How local processing works
- Your PDF is processed in your browser using local JavaScript libraries.
- PDFWhisk does not upload your file to a processing server for supported tools.
- Only normal page assets load from the site (HTML/CSS/JS), not your document contents.
Selected files
Page preview
Ready to download
Support: hello@pdfwhisk.com (reply in ~24h)
Security & privacy detailsHow this tool helps
Reduce the file size of your PDF documents instantly, right in your browser. Our PDF compressor uses smart optimization to shrink files by up to 90% while preserving text clarity, image quality, and formatting. Perfect for email attachments, uploading to portals, or saving storage space. Unlike other tools, your PDF never leaves your device - all compression happens locally using your browser's processing power. Choose from three quality levels: high compression for maximum size reduction, balanced for the best mix of quality and size, or low compression to keep near-original quality. Works with scanned documents, reports, presentations, and any PDF file. Use it when you need to split large PDFs for portal limits, compress PDFs on iPhone, reduce email attachment size.
Best for
How it works
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1
Upload your PDF
Drop your file into the upload area or tap to browse from your device.
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2
Choose a target and run compression
Pick your target size (or custom size), then run the tool. PDFWhisk tries multiple local optimisation passes.
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3
Review and download
Check the before/after file sizes and quality note, then download the compressed PDF.
Frequently asked questions
How much can I compress a PDF?
Typical compression reduces file size by 40-90%, depending on the content. PDFs with large images see the biggest reductions. Text-only PDFs are already quite small and may only shrink by 10-20%.
Does compression reduce quality?
You control the quality level. 'Balanced' mode provides excellent quality at significantly reduced size. 'Maximum' compression will noticeably reduce image quality but produces the smallest files. Text remains sharp at all levels.
Is there a file size limit?
Since processing happens in your browser, the limit depends on your device's memory. Most devices handle PDFs up to 100MB comfortably. For very large files, try splitting them first.
Are my files uploaded to a server?
No. Your PDF is processed entirely in your browser. The file never leaves your device. We cannot see, access, or store your documents.
Can I compress multiple PDFs at once?
The free version processes one file at a time. Pro users can batch-compress multiple PDFs simultaneously.
What to do next
Chain tools together for a complete workflow.
Popular searches for this tool
Intent-specific pages for common real-world tasks (upload limits, email attachments, iPhone workflows, and privacy-first processing).