Compress PDF
Most PDF compressors upload your file to their server. This one runs entirely in your browser using pdf-lib — no upload, no tracking.
About PDF compression
PDF file size is dominated by embedded images and font subsets. Most online compressors re-encode images as lower-quality JPEGs — visually fine, but loses text-selectability and uploads your file to their server. The Qaynaq Labs PDF Compressor runs entirely in your browser with pdf-lib.
Smart mode re-saves the PDF with optimized object streams — this catches PDFs that were generated inefficiently and shrinks them ~5-15% without quality loss. Raster mode (coming in a future version) would render every page to a JPEG and rebuild the PDF — maximum shrinkage but loses selectable text. For text-heavy PDFs that are already well-compressed, no online tool can save much without quality loss.
Frequently asked
Why isn't my PDF much smaller after compression?
If the PDF is mostly text or already well-compressed, there's no slack to remove. PDFs from Word, LaTeX, and most modern generators are already optimized. The biggest wins are scan-PDFs (lots of images).
Will I lose text selectability?
Smart mode: no. Raster mode (not yet shipped): yes — every page becomes a JPEG image, no more selectable text.
Does my file upload?
No. Everything runs in your browser using pdf-lib. Open DevTools then Network to verify — no upload requests fire.
What about password-protected PDFs?
If the password is removable (owner password only), yes. User-password-protected PDFs need to be unlocked first.