Compress PDF
Reduce PDF file size without losing quality. Compress large PDFs for email, upload, or storage — all processing happens in your browser.
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🔒 Your files are private. All processing happens locally in your browser. Files are never uploaded to any server.
FAQ
Frequently asked questions.
Upload your PDF using the file picker or drag-and-drop area. Select your desired compression level — Light, Medium, or Strong. Click the Compress button and download your optimized PDF. The entire process runs in your browser with no file uploads to any server.
The reduction depends on PDF content. PDFs with many high-resolution images can typically be reduced by 50–80%. Text-heavy PDFs compress less dramatically but still see 10–30% reduction. Strong compression mode maximizes size reduction at the cost of slightly lower image quality.
Text quality is never affected by PDF compression — text is stored as vector data and always remains sharp and crisp at any zoom level. Only embedded images are compressed. Using Light or Medium compression modes, image quality loss is barely noticeable to the human eye.
Light compression applies minimal image optimization while preserving near-original quality — ideal for professional documents. Medium compression offers a balanced trade-off between size and quality for general use. Strong compression aggressively reduces image resolution to achieve maximum file size reduction, best for documents that will be viewed on screen.
You can compress PDFs up to 200MB in size. For extremely large files, compression may take 30–60 seconds since it runs entirely in your browser. We recommend closing other tabs for better performance with very large files.
Yes, completely private. Our PDF Compressor runs entirely in your browser using WebAssembly and JavaScript. Your files are never transmitted to any server, cloud service, or third party. Everything happens locally on your device.
Yes. The tool works in any modern mobile browser. Open the tool on your smartphone, upload your PDF from your device or a cloud storage app, select compression level, and download the compressed file — all without installing any app.
If your PDF is already optimized, contains mostly text, or uses vector graphics with no embedded raster images, compression may have minimal effect. Some PDFs are already using efficient encoding internally. Try Strong compression mode for maximum reduction.
Yes. Scanned PDFs are essentially images embedded in a PDF container, so they compress very well — often 60–80% reduction. Use Medium or Strong compression mode for scanned documents. For even better results, consider converting the scanned PDF to images first using PDF to Image.
Yes. The PDF Compressor is 100% free with absolutely no watermarks added to your output file, no file limits, no sign-up required, and no premium tier. Your compressed PDF is clean, professional, and ready to share or submit.