PDF Compressor
Reduce PDF file size in your browser by packing objects into compressed streams and stripping unused metadata.
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What is PDF Compressor?
The PDF Compressor is a free, browser-based tool that reduces the file size of a PDF document. By packing internal objects into compressed object streams and optionally stripping unused metadata, it produces a leaner PDF without installing any software. Everything runs locally in your browser, so your files stay private.
Key Benefits
- Shrink PDF file size for easier email and web sharing
- Three compression levels from light cleanup to aggressive stream packing
- 100% private — files are processed locally and never uploaded
- No sign-up, no watermarks, completely free
- Preserves visual quality — does not re-encode embedded images
Common Use Cases
- •Reducing PDF size to meet email attachment limits
- •Speeding up PDF uploads to web forms and portals
- •Slimming down generated reports before archiving
- •Preparing lightweight PDFs for websites and downloads
- •Cleaning up metadata-heavy PDFs exported by design tools
How to Compress a PDF
- Upload your PDF: Drag and drop your PDF file onto the upload area, or click to browse and select it.
- Choose a compression level: Pick Low, Medium, or High. High packs objects into compressed streams and strips metadata for the smallest output.
- Compress: Click "Compress PDF". The tool processes the file entirely in your browser.
- Download: Review the before/after sizes and percentage saved, then click "Download Compressed PDF" to save the result.
Key Features
- Three compression levels: Low, Medium, and High
- Live before/after size comparison with percentage saved
- High level strips document metadata (title, author, dates) for extra savings
- 100% client-side — your PDF never leaves your browser
- Drag-and-drop upload with instant page detection
- One-click download of the compressed PDF — no server round-trip
Frequently Asked Questions
Are my PDF files uploaded to a server?
No. This tool uses the pdf-lib library to compress PDFs entirely in your browser. Your file never leaves your device.
How much can the file size be reduced?
It depends on the source PDF. PDFs that were not already optimized can shrink noticeably, but files that already use compressed object streams or contain large embedded images may see little or no reduction.
What is the difference between Low, Medium, and High?
Low keeps the original object layout with light optimization. Medium packs objects into compressed streams. High additionally strips document metadata such as title, author, and dates for the smallest output.
Does this re-compress or lower the quality of images in the PDF?
No. This tool optimizes the PDF structure (objects and metadata) but does not re-encode or downscale embedded images, so visual quality is preserved.
Featured in Collections:PDF & Document Processing Suite