Compress PDF
Reduce a PDF's file size by optimizing its internal structure, right in your browser. Compress a single PDF, or switch to Bulk mode to compress many PDFs at once and download them all as a ZIP. Nothing is uploaded to a server.
How compression works
This tool rebuilds the PDF using compact object streams and removes duplicate internal objects, which meaningfully shrinks PDFs with repeated fonts or resources.
What it doesn't do
It does not re-encode embedded images - that requires server-side raster recompression, which isn't possible purely in the browser. For image-heavy PDFs, savings will be smaller than for text-heavy ones.
Bulk mode
Bulk mode compresses every selected PDF with the same settings and bundles all the results into a single ZIP download.
Common Mistakes to Avoid
Expecting large savings on a PDF full of scanned images
Solution:
Structural compression mainly helps text-heavy PDFs with repeated resources. Image-heavy scans will see smaller reductions.
Compressing an already-optimized PDF expecting further gains
Solution:
If a PDF was already saved efficiently, there may be little left to trim - the result will be close to the same size.
Frequently Asked Questions
No - this is a structural, lossless optimization. Text, fonts, and images are not degraded.
Yes - switch to Bulk mode to compress multiple PDFs at once and download them together as a ZIP.
How compression works
This tool rebuilds the PDF using compact object streams and removes duplicate internal objects, which meaningfully shrinks PDFs with repeated fonts or resources.
What it doesn't do
It does not re-encode embedded images - that requires server-side raster recompression, which isn't possible purely in the browser. For image-heavy PDFs, savings will be smaller than for text-heavy ones.
Bulk mode
Bulk mode compresses every selected PDF with the same settings and bundles all the results into a single ZIP download.