Compress PDF Online Free - Reduce PDF Size
Reduce PDF file size by removing redundant data and optimizing structure. Shows before/after size comparison. 100% browser-based, no upload required.
Click or drag a PDF file here
Upload one PDF file to compress. All processing is done locally in your browser.
What is PDF Compression?
PDF compression reduces the file size of a PDF by removing redundant internal objects and optimizing the document structure using object stream compression. This works especially well on PDFs generated by software that leaves unreferenced data behind. The tool runs entirely in your browser using pdf-lib, so your file is never uploaded anywhere.
How to Compress a PDF
- Click the upload area or drag and drop your PDF file
- Click 'Compress PDF' to start the optimization
- Review the before and after file sizes shown in the results
- Click 'Download Compressed PDF' to save the optimized file
PDF Compress Features
- Removes redundant and unreferenced internal PDF objects
- Applies object stream compression to reduce structural overhead
- Shows original size, compressed size, and percentage reduction
- 100% browser-based — your PDF never leaves your device
- No file size limit imposed by the tool
Compress PDF FAQ
Is my PDF data secure during compression?
Yes! All compression happens entirely in your browser. Your files are never uploaded to any server, ensuring complete privacy.
Why didn't my PDF get smaller?
This tool compresses the PDF's internal structure and removes redundant objects. If your PDF is already well-optimized or consists mainly of embedded images, there may be little or no size reduction possible with structural compression alone.
Will compression affect my PDF's content or quality?
No. This tool only restructures the internal object layout of the PDF. Text, images, fonts, and all content remain completely unchanged.