Three Compression Levels
Choose Basic (lossless metadata cleanup), Recommended (re-encode images at 70% quality), or Strong (re-encode at 40% quality)
Compress PDF Files Online
Reduce PDF file size by re-encoding embedded images at adjustable quality levels. Choose from three compression levels: Basic, Recommended, and Strong. All processing happens locally in your browser.
Why Choose Our PDF Compressor?
Fast, private, and free PDF compression powered by browser-side processing
100% Private
All compression happens locally in your browser. Your PDF files are never uploaded to any server
Image Re-encoding
The main size reduction comes from re-encoding embedded JPEG images at lower quality. Text and vector graphics are preserved
Instant Compression
Powered by pdf-lib for fast processing. Get your compressed PDF in seconds
Works Everywhere
Runs on Windows, macOS, Linux, Android, and iOS. Any modern browser is supported
Completely Free
No registration, no watermarks, no file limits. Free for personal and commercial use
How to Compress PDF
Three simple steps to reduce your PDF file size
1
Upload PDF File
Click the upload area or drag and drop a PDF file. The original file size will be displayed.
2
Choose Compression Level
Select Basic, Recommended, or Strong compression. Higher levels reduce file size more aggressively.
3
Compress and Download
Click the Compress button. Your compressed PDF will be generated and ready for download instantly.
Frequently Asked Questions
Everything you need to know about compressing PDF files
How does PDF compression work?
Our tool reduces PDF size in two ways: 1) Cleaning up unused metadata and objects (all levels); 2) Re-encoding embedded JPEG images at lower quality (Recommended and Strong levels). Text, vector graphics, and PNG images are preserved losslessly.
Are my PDF files uploaded to a server?
No. All PDF compression happens entirely in your browser using the pdf-lib library. Your files never leave your device, ensuring complete privacy.
What is the difference between Basic, Recommended, and Strong?
Basic only removes unused objects and metadata - minimal size reduction but lossless. Recommended re-encodes JPEG images at 70% quality - good balance of size and quality. Strong re-encodes at 40% quality - maximum size reduction, noticeable image quality loss.
Will compression affect text quality?
No. Text and vector graphics are preserved exactly as they were in the original PDF. Only embedded raster images (JPEG) are re-encoded at lower quality in Recommended and Strong modes.
Why is my PDF not getting smaller?
If your PDF contains mostly text and vector graphics with no embedded images, there is little to compress. PDFs with many high-resolution photos will see the most significant size reduction.
Is there a file size limit?
There is no hard limit, but processing very large PDFs (over 100MB) may consume significant browser memory. For best performance, compress PDFs under 50MB at a time.