Compress PDF — Advanced PDF Compressor

Compress PDF — Reduce PDF File Size Online

Shrink your PDF files without losing too much quality. Our advanced compressor renders each page at optimized resolution and re-embeds them as compressed images. Choose from 4 compression levels to find the perfect balance between file size and quality.

How PDF Compression Works

The tool uses pdf.js to render each PDF page to a canvas element at a resolution determined by your chosen compression level. It then converts those canvases to JPEG images and uses pdf-lib to assemble a new, smaller PDF. This approach is especially effective for PDFs with large images or complex graphics.

Compression Levels Explained

Low: Minimal compression at high DPI. Best for documents where quality matters most.

Medium: Balanced compression. Good for most everyday documents.

High: Aggressive compression at lower DPI. Good for email attachments.

Maximum: Smallest possible file size. Quality may be noticeably reduced.

Frequently Asked Questions

The tool renders each PDF page to a canvas at a reduced resolution based on your chosen quality level, then re-embeds those pages as optimized JPEG images into a new PDF, reducing overall file size.

Four levels: Low (minimal compression, best quality), Medium (balanced), High (smaller size, lower quality), and Maximum (smallest size, lowest quality).

No, all compression happens entirely in your browser using pdf.js and pdf-lib. Your files are never uploaded anywhere.

Since pages are re-rendered as images, text becomes part of the image. Lower quality levels may make text slightly less sharp. Use Low or Medium for documents where text readability is important.