PDF Tools

Free PDF Compressor Online — Reduce PDF File Size Instantly

Compress PDF files by up to 80% without losing readability. Choose from three compression levels, strip hidden metadata, and batch process multiple files at once. Everything runs in your browser — your documents are never uploaded to any server.

  • ✓Batch compress multiple PDFs simultaneously
  • ✓3 compression levels: Light, Medium and Maximum
  • ✓Remove embedded metadata to shrink file size
  • ✓Real-time before/after file size comparison
  • ✓Download compressed files individually or as ZIP
  • ✓Your PDFs never leave your device — 100% private
Remove metadata
Strips author, creator, dates — extra size savings
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Drop PDF files here or click to browse
Supports multiple files · Max recommended 100 MB each
Add PDF files above to get started

How to Compress a PDF Online

1
Choose compression level
Pick Light for maximum compatibility, Medium for a good balance, or Maximum for the smallest file size.
2
Upload your PDFs
Drag and drop one or more PDF files into the upload area, or click to browse your device.
3
Click Compress
The tool processes all files in your browser. Watch the before/after size appear for each file.
4
Download results
Download each compressed PDF individually, or grab all of them at once in a single ZIP file.

❓ Frequently Asked Questions

How does browser-based PDF compression work?+
Our compressor uses pdf-lib to re-encode your PDF using efficient object streams, removes redundant data structures, and strips embedded metadata. This reorganises the file's internal structure to be more compact. For text-heavy PDFs, savings of 10–50% are typical. For PDFs with embedded images or already heavily optimised files, savings may be smaller — the compressor won't degrade image quality.
Will compression reduce the visual quality of my PDF?+
No. Our compression is lossless — it targets the file structure, not the content. Text, vector graphics and embedded fonts remain pixel-perfect. If your PDF contains raster images, those images are re-encoded at their original quality. The 'Maximum' level strips more metadata and uses tighter object packing, which may slightly affect compatibility with very old PDF readers but has no effect on visual quality.
What is PDF metadata and should I remove it?+
PDF metadata includes the author name, creation software, creation date, modification date and custom properties. This information is invisible to readers but adds to file size. Removing it is safe for most use cases — documents you're sharing publicly, submitting to web forms or emailing. Keep metadata if you need to track document versions or if it's required for compliance (e.g., legal filings).
Why is my compressed PDF larger than the original?+
This can happen with PDFs that are already optimised, or PDFs where re-encoding adds overhead. pdf-lib rewrites the file structure, which occasionally adds a small fixed overhead. If this happens, the tool will show a '0% savings' result — always compare sizes before replacing your original file.
Is there a file size limit?+
There is no hard limit — processing happens entirely in your browser using your device's RAM. Very large PDFs (over 200MB) may be slow to process on lower-powered devices. For best performance, we recommend processing files under 100MB per batch. All processing is private — your files never touch our servers.