Is my PDF uploaded to a server?

No — compression runs entirely in your browser with pdf.js and pdf-lib, so the document never leaves your device.

Why did "Downsample images" shrink my PDF so much?

It re-renders every page as a JPEG at the DPI and quality you pick, which dramatically reduces size for scanned or image-heavy PDFs. The trade-off is that text becomes part of the image and is no longer selectable.

When should I use "Lossless re-stream" instead?

Use it for text or vector PDFs you want to keep editable/searchable. It rebuilds the file with compact object streams and removes metadata, giving modest savings without quality loss.

What if the file gets bigger or barely changes?

Some PDFs are already optimized. The tool shows the before/after sizes and percentage so you can compare — try the other method or a lower DPI/quality if needed.

PDF Compressor

Make PDFs smaller without uploading them anywhere. Downsample page images to a chosen DPI and JPEG quality for big savings on scans and image-heavy documents, or re-stream losslessly to rebuild the file with compact object streams and stripped metadata while keeping text and vectors intact.

How to use PDF Compressor

Drop in your PDF (or click to browse).
Choose "Downsample images" for maximum shrinkage, or "Lossless re-stream" to keep selectable text.
Tune the DPI/quality (or the metadata option), click Compress, and download the smaller PDF.

Frequently asked questions

Is my PDF uploaded to a server?: No — compression runs entirely in your browser with pdf.js and pdf-lib, so the document never leaves your device.
Why did "Downsample images" shrink my PDF so much?: It re-renders every page as a JPEG at the DPI and quality you pick, which dramatically reduces size for scanned or image-heavy PDFs. The trade-off is that text becomes part of the image and is no longer selectable.
When should I use "Lossless re-stream" instead?: Use it for text or vector PDFs you want to keep editable/searchable. It rebuilds the file with compact object streams and removes metadata, giving modest savings without quality loss.
What if the file gets bigger or barely changes?: Some PDFs are already optimized. The tool shows the before/after sizes and percentage so you can compare — try the other method or a lower DPI/quality if needed.