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Free PDF Tool

Compress PDF Online Free

Reduce your PDF file size quickly and easily. Choose from multiple compression levels. 100% client-side processing means your files never leave your device.

PDF Compressor

Drop your PDF here

or click to browse

Max 100MB
How It Works

Simple 3-Step Process

Compress your PDF files in seconds without uploading to any server.
  • 1. Upload Your PDF
    Drag and drop or click to select your PDF file. Files up to 100MB are supported.
  • 2. Choose Compression
    Select your preferred compression level based on your quality and size needs.
  • 3. Download Result
    Get your compressed PDF instantly. No waiting, no email required.
Why Use This Tool

Fast, Private, Free

Our PDF compressor runs entirely in your browser for maximum privacy and speed.

100% Private

Your files never leave your device. All processing happens locally in your browser.

Instant Processing

No upload/download wait times. Compression starts immediately on your device.

No Limits

Compress as many PDFs as you want. No daily limits, no account required.

About PDF Compression

This tool uses pdf-lib to optimize PDF structure by removing unused objects and enabling object streams. The actual compression achieved depends on your PDF's content:

  • Works well: PDFs with redundant data, unoptimized structure, or text-heavy content
  • Limited effect: Already-optimized PDFs or image-heavy documents (images are not recompressed)
FAQ

Frequently Asked Questions

Common questions about compressing PDF files online.
How much smaller will my PDF file be after compression?
The compression ratio depends on your PDF's content. Text-heavy documents and unoptimized PDFs can see reductions of 20-50% or more. Image-heavy PDFs or already-optimized files may see smaller reductions (0-10%) since our browser-based tool focuses on structural optimization rather than image recompression.
Will compression affect the quality of my PDF?
Our compression tool optimizes the PDF structure without altering visual quality. It removes redundant data and enables efficient object streams. Images, text, and graphics remain at their original quality. For aggressive image compression, you may need server-based tools.
Is it secure to compress my PDF online?
Absolutely. Our PDF compressor runs entirely in your web browser using JavaScript. Your files are never uploaded to any server - all processing happens locally on your device. This means your sensitive documents remain completely private and secure.
What's the maximum file size I can compress?
You can compress PDF files up to 100MB in size. Since processing happens in your browser, very large files may take longer depending on your device's capabilities. For files larger than 100MB, consider splitting them first using our free Split PDF tool.
How does PDF compression work?
PDF compression works by optimizing the internal structure of the document. Our tool uses object streams to combine multiple objects into compressed streams, removes unused objects and redundant data, and reorganizes the file structure for efficiency. This structural optimization can significantly reduce file size without touching the actual content.
Why is my PDF not getting much smaller?
Some PDFs are already well-optimized or contain content that cannot be further compressed without quality loss. Image-heavy PDFs often fall into this category since our browser-based tool preserves image quality. If you need aggressive compression for image-heavy PDFs, consider using server-based tools that can recompress embedded images.
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