PDF Compressor

Compress PDF Files Free — Reduce PDF Size Online

Free online PDF compressor — reduce the file size of any PDF for email attachments, course submission portals, or storage. Choose from low, medium, or high compression. No sign-up required. Your file never leaves your browser.

Last updated: April 2026  ·  Powered by pdf-lib

Drop your PDF here or click to browse

PDF files only

Max file size: 100MB

Compression Level

Best results on PDFs with images. Text-only PDFs may see minimal reduction.

Processing... 0%
Compression Results
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Original Size
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Compressed Size
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Size Reduction

Compressed PDF Ready!

Your PDF has been compressed. Click to download.

Privacy guaranteed: PDF compression runs entirely in your browser using PDF.js and pdf-lib. Your file is never uploaded to any server.
Important — Watermarks & Copyright: This tool re-renders PDF pages as compressed images. Watermarks embedded in the original PDF will remain visible — this tool does not remove them. Only compress PDFs you own or have explicit permission to modify. You are solely responsible for ensuring lawful use.

How It Works

  • 1
    Upload your PDF file
  • 2
    Choose compression level
  • 3
    Click Compress — images are re-rendered at lower quality
  • 4
    Download your smaller PDF instantly

Other Tools

Why Compress a PDF Before Submitting?

Most university portals, scholarship applications, and job platforms cap uploaded file sizes at 2 MB, 5 MB, or 10 MB. Scanned PDFs can easily exceed those limits. Our free PDF compressor reduces file size by up to 90% — letting you meet upload limits without paying for Adobe Acrobat or iLovePDF.

The compressor re-renders each PDF page as a compressed image using PDF.js and pdf-lib, entirely inside your browser. You choose the compression level — low (best quality), medium (balanced), or high (smallest file). No file is ever sent to a server.

Common uses: compressing scanned transcripts for university applications, reducing portfolio PDFs for email attachments, shrinking multi-chapter reports for online submission portals, and archiving large PDFs on limited storage devices.

Frequently Asked Questions

Is the PDF compressor really free?

Yes — 100% free with no sign-up, no watermarks, and no paid tier. It runs entirely in your browser using open-source libraries.

What do the compression levels mean?

Low compression gives a modest size reduction while keeping quality high. Medium balances size and quality. High gives the smallest file size, which may reduce image quality in the PDF.

Is there a file size limit?

The tool supports PDFs up to 100MB. Larger files may be slow to process depending on your device.

Are my files sent to a server?

No. Everything runs inside your browser. Your PDF is never uploaded to any server and is deleted from memory when you close the tab.

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