How much can I expect to compress a typical PDF?

Text-heavy PDFs may reduce by 10-25 percent. Image-heavy PDFs on high compression can reduce by 40-70 percent.

Does compression affect text quality?

No. Text is vector data and is not affected by compression. Only embedded raster images may be affected.

What is garbage collection in PDF?

PDFs accumulate unused objects from editing. Garbage collection removes these dead references reducing file size.

When should I use high compression?

Use high compression for archive copies, email attachments, or sharing where small file size matters more than image sharpness.

Will the compressed PDF still be printable?

Yes. All content remains fully printable. High compression may slightly reduce print sharpness for embedded photos.

Can I compress a password-protected PDF?

No. Protected PDFs cannot be processed.

What if compression makes the file larger?

If the compressed size exceeds the original the tool returns the original unchanged with a notification.

Does it compress scanned PDFs?

Yes. High compression is especially effective on scanned PDFs with embedded images.

Is my PDF stored on the server?

No. Processing is in-memory and files are discarded immediately.

Can I further compress an already-compressed PDF?

Each subsequent compression yields diminishing returns. After one medium compression most gains are already captured.

Does this work for PDFs with embedded fonts?

Yes. Embedded font data is handled by PyMuPDF cleanly without affecting readability.

How does 150 DPI image downsampling work?

Embedded images above 300 DPI are resampled to 150 DPI reducing their byte size while keeping reasonable visual quality.

Can I compress multiple PDFs at once?

Single file per request currently. Use the tool multiple times for multiple files.

Does it remove watermarks or restrictions?

No. This tool only compresses file size and does not alter content or permissions.

What is deflate compression in PDF context?

Deflate is a lossless data compression algorithm applied to PDF stream data reducing encoded overhead.

Free PDF Compressor — Reduce PDF File Size Online

Drop PDF or click to upload

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About PDF Compressor

PDF Compressor reduces PDF file size using PyMuPDF\'s advanced garbage collection, deflate compression, and optional image downsampling without requiring any external services. Three compression levels let you choose the right trade-off: low compression is nearly lossless and best for contracts and legal documents, medium compression is the recommended balanced option for reports and presentations, and high compression aggressively downsamples embedded images to 150 DPI which is ideal for archive copies where visual quality can be slightly reduced. The tool always shows original size, compressed size, and exact percentage reduction.

Key Features

Three Compression Levels
Low, medium, and high compression levels for different quality and size trade-off requirements.
Image Downsampling
High compression mode resamples embedded images to 150 DPI reducing large-image PDFs significantly.
Garbage Collection
Removes unused objects, streams, and cross-reference data accumulated from editing history.
No-Reduction Detection
If the compressed file is larger than the original the tool returns the original with a notification.
Size Comparison Display
Shows before and after file size with visual bar and exact percentage reduction.
Large File Support
Handles PDFs up to 50 MB including complex multi-hundred-page documents.

How to Use

1
Upload your PDF
Select a PDF up to 50 MB. File size is shown after upload.
2
Select compression level
Choose Low for near-lossless, Medium for balanced, or High for maximum compression.
3
Click Compress
Processing time varies from 1 second to 30 seconds depending on file size and level.
4
Review size reduction
See original size, compressed size, and percentage reduction in the result card.
5
Download compressed PDF
Download the optimized file which opens and displays identically to the original.

Real-World Use Cases

Email Attachment Size Reduction

A consultant compresses a 15 MB presentation PDF to under 5 MB to meet email attachment limits.

Website Upload Optimization

A real estate agent compresses property brochure PDFs before uploading to a listing website.

Archive Compression

An archivist uses high compression on scanned historical documents reducing storage needs by 60 percent.

Frequently Asked Questions

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