PDF Compressor

What is the Free PDF Compressor?

The free PDF Compressor reduces PDF file size by re-saving the document with optimised internal structure — entirely in your browser with no upload. Drop your PDF and click Compress & Download. The tool uses pdf-lib's optimised save mode, which removes duplicate objects, rewrites cross-reference tables as compressed streams, and strips unnecessary internal data. After compression, a result card shows the original size, compressed size, and the savings percentage (or a note if the file is already well-optimised).

• → Reducing a PDF file size before emailing it to stay under attachment limits
• → Compressing a PDF that was repeatedly saved in different editing tools (which adds bloat)
• → Reducing the storage footprint of large PDF archives
• → Optimising PDFs created by desktop publishing or CAD software for web distribution

How to Use the Free PDF Compressor

1. 1 Drop or select your PDF in the drop zone.
2. 2 Read the short explanation of how the compression works.
3. 3 Click Compress & Download.
4. 4 The compressed PDF downloads automatically and a result card shows the savings: ✅ reduced by N% or ⚠️ already optimised.

Key Features

• 📉
  Structure-level compression

  Removes duplicate objects, rewrites cross-reference tables, and strips unused data without altering content.
• 📊
  Before/after size comparison

  Result card shows original size, compressed size, and percentage saved.
• ⚠️
  Honest already-optimised notice

  If the file is already minimal, the tool tells you rather than pretending to compress it.
• 🔒
  Free, browser-based

  All compression runs locally using pdf-lib — your PDF is never uploaded to any server.
• 🆓
  No watermarks or sign-up

  No account required and no watermarks are added to the compressed output.

Example Usage

File: edited-report.pdf — 4.2 MB (repeatedly saved in multiple tools)

edited-report-compressed.pdf — 1.8 MB (57% reduction)

Frequently Asked Questions about the Free PDF Compressor

What is the free PDF Compressor?

Reduce the file size of PDF documents for easier sharing.

Is the PDF Compressor free to use?

Yes, the PDF Compressor is completely free. No account, subscription, or signup is required — ever.

Does my data get uploaded anywhere?

No. The PDF Compressor runs entirely in your browser. Your data is never sent to any server.

Does it work offline?

Yes. Once the page has loaded, the tool works without an internet connection.

Which browsers are supported?

All modern browsers — Chrome, Firefox, Safari, and Edge. No plugins or extensions required.

What types of PDFs does this compressor work best on?

It works best on PDFs that have been repeatedly edited or saved in multiple tools (e.g. Adobe Acrobat, Word, LibreOffice), which accumulate redundant internal objects. PDFs that were originally created from direct export (e.g. "Save as PDF" from a word processor) are usually already close to minimal size.

Does this compressor reduce image quality inside the PDF?

No — this tool compresses PDF structure, not embedded images. It does not re-encode or downscale any images. For maximum compression on image-heavy PDFs, combining this with lower-resolution images at source will yield better results.

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