PDF Compressor — Reduce PDF File Size Online Free
Free online PDF compressor to reduce PDF file size without losing quality. Compress images, remove metadata, and optimize documents for email or web upload. Choose compression level and shrink your PDF instantly — 100% client-side and private.
100% client-side. Your PDF is compressed entirely in the browser — nothing is uploaded to any server.
Compression Level
Advanced Options
Remove metadata
Title, author, keywords, dates
Remove annotations
Comments, highlights, links
Remove form fields
Interactive AcroForm fields
Image Compression
Downsample images
Scale images above max DPI threshold
Output filename
What gets compressed
✓PDF metadata (title, author, keywords)
✓Object stream compression (pdf-lib)
✓Re-encode embedded JPEG images
✓Optional: annotations, form fields
–Cannot re-compress FlateDecode streams (browser limitation)
–Cannot render pages to bitmap (requires full PDF renderer)
Drop a PDF file here
or click to browse
How to Use PDF Compressor
Upload a PDF
Drop or upload the PDF file you want to compress.
Choose compression level
Select Light, Medium, or Aggressive compression depending on your quality vs size preference.
Configure advanced options
Optionally remove metadata, annotations, or form fields. Adjust image quality and DPI settings.
Download compressed PDF
Click 'Compress PDF' and download your optimized file — no uploads, 100% private.
Frequently Asked Questions
Reduction depends on the original file. PDFs with large embedded JPEG images can shrink 50-80% with Aggressive compression. Metadata-only PDFs may see only minor gains.
Light mode removes metadata only with no quality loss. Medium re-encodes JPEGs with good quality. Aggressive uses lower JPEG quality for maximum size reduction.
No. Everything runs client-side in your browser using pdf-lib. Your file never leaves your device.
Most files under 50 MB complete in seconds. Larger files with many images may take longer since all processing happens locally.
There is no hard limit, but extremely large files may be limited by browser memory. Files up to 100 MB generally work well in modern browsers.
Yes, but scanned PDFs often contain FlateDecode-encoded images which cannot be re-compressed client-side. You may see limited reduction on these files.
Advanced options can remove title, author, keywords, creation date metadata, annotations (comments, highlights), and interactive form fields.
Try an Example
Sample file
my report.pdf
~5.2 MB → ~2.1 MB with Medium compression
60% size reduction achieved
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