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What Is PDF Compressor?

PDF Compressor reduces the file size of your PDF documents while preserving visual quality. Whether you need to meet email attachment limits, speed up page loads, or save storage space, this tool handles compression without degrading readability.

How to Use This Tool

Upload your PDF, choose a compression level (low, medium, or high), and click compress. The tool processes your file in-browser using client-side JavaScript, then provides a download link with the compressed result. You’ll see the before-and-after file sizes so you can gauge the reduction.

Why Use PDF Compressor?

Most online compressors upload your files to remote servers, creating privacy risks for sensitive documents. This tool runs entirely in your browser — no data leaves your device. There are no file size caps, no watermarks, and no account required. For a detailed walkthrough, see our step-by-step guide.

The compression engine used here applies the same standard PDF object-stream and image-recompression techniques that a desktop tool like Acrobat or a server-side library like Ghostscript would apply, but the entire pipeline runs locally in the browser. That matters most for the files that are most commonly compressed — signed contracts, scanned tax returns, medical records, board decks — because those are exactly the files no operator should be uploading to a free third-party service in the first place. Output quality is configurable: a single preset slider that maps to image DPI and JPEG quality factors, with a side-by-side preview so you can see the cost in detail before saving.

Frequently Asked Questions

How does browser-based PDF compression work?+
The tool renders each PDF page to a canvas at your chosen quality level, then rebuilds the PDF with compressed images. This reduces file size while keeping text sharp.
Will compression reduce my PDF quality?+
You control the quality level. High quality preserves most visual detail with moderate compression. Lower quality settings achieve smaller files but may affect image clarity.
Is my PDF uploaded to a server?+
No. Everything runs in your browser. Your files stay on your device.
How much can I expect to shrink a PDF?+
It depends on the content. Scanned documents with embedded images often shrink 60–80%; text-only PDFs may only drop 5–15% because text is already efficiently encoded.
Does compression reduce text quality?+
No. Text remains vector-encoded at full fidelity. Compression operates on embedded images by re-encoding them at lower JPEG quality and downsampling DPI, and on font subsetting to remove unused glyphs.
Which compression level should I pick?+
For email attachments and most web sharing, medium (recommended) hits the best size/quality balance. Use high for archival print where image detail matters; use maximum for thumbnail previews or text-only forms where size dominates.
Can I batch-compress multiple PDFs?+
Drop multiple files into the upload zone. Each is processed sequentially and bundled into a single zip download. Heavy batches may take a minute on slower devices.
Does compression strip metadata?+
Optional. By default, title and author metadata are preserved; an "Aggressive" toggle removes XMP metadata, embedded thumbnails, and PDF/A markers for additional savings.

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