Compress PDF Online
Optimize your PDF's internal structure to reduce file size. See the before and after instantly — free and 100% private.
Frequently Asked Questions
How does the PDF compression work?
The tool reorganizes the PDF's internal object structure using object streams (a PDF standard optimization). This reduces overhead in the file's cross-reference tables and can meaningfully reduce size for text-heavy PDFs.
Why didn't my PDF get smaller?
Results depend heavily on the file type. PDFs that are already optimized, scanned documents, or files where the bulk of size comes from embedded images may see little to no reduction. This tool optimizes PDF structure, not image data.
Can I compress a scanned PDF?
You can run it through the compressor, but scanned PDFs are essentially image containers. Since the tool does not resample images, size reduction will typically be minimal for scan-heavy files.
Is this lossless? Will the compressed PDF look different?
Yes, the compression is completely lossless. Text, images, and all visual content remain identical. Only the internal file structure is reorganized.
Are my files uploaded during compression?
No. Everything runs inside your browser. Your PDF is never sent to any server, and nothing is stored after you close the page.