Shrink your PDF by losslessly optimizing its internal structure, no image quality loss. The result is local; nothing is sent to a server.
Reduce the size of a PDF with pdf-lib. Pick your file and download a leaner version.
pdf-lib rebuilds the document with object streams and Flate (zlib) compression applied to every content stream, which trims PDFs that were saved with uncompressed or inefficiently packed data. It is lossless structural compression, no page is rasterised, so the text layer stays selectable and searchable; files that are already optimally compressed will shrink little.
No. The PDF is loaded and rebuilt by pdf-lib running inside this browser tab, your document is read into memory on your own device, recompressed there, and the leaner file is offered as a local download. Nothing is sent to Sunasty or any third party. Confirm it yourself: open DevTools, go to the Network tab and watch, no request carries your document.
pdf-lib re-saves the document with object streams enabled and applies Flate (zlib) compression to every content stream. The biggest savings come from PDFs exported with uncompressed or redundant data; a file that is already tightly packed may barely change in size. It is lossless structural compression, no page is rasterised or downgraded.
Yes. The compression only re-packs the existing streams; the text layer, fonts and document structure are preserved, so selecting and searching keep working exactly as before.
Yes, once the page has loaded. Because the processing happens on your device, you can disconnect from the network and the tool keeps working. This is the clearest proof that your data never leaves your machine.
It is completely free and requires no sign-up. There are no watermarks, no daily limits and no tracking cookies needed to use the tool.