PDF Compressor

Upload compressors send the entire file — often containing IDs, resumes, or internal reports — to a remote server. This tool finds embedded images, re-encodes them with the Canvas API, and rewrites the PDF with pdf-lib entirely on your device. You avoid upload latency and keep sensitive attachments out of third-party storage.

Most size wins come from downsampling and JPEG re-encoding of photo-like images inside the PDF. Stronger compression uses a lower JPEG quality and a smaller max dimension, which shrinks files further but can soften fine detail. Pick Low when print fidelity matters, Recommended for everyday uploads, and Extreme when a portal’s size limit is the hard constraint.

Low Compression keeps image resolution at 100% and re-encodes JPEGs at quality 0.85. Recommended (default) caps images at 1500px on the long edge with quality 0.65. Extreme caps at 1000px with quality 0.40. In each case, image XObjects are swapped for lighter embedJpg streams when the new bytes are smaller.

If the file is mostly text/vector content, there may be little or nothing to downsample — the tool finishes without error, preserves the document, and reports the resulting size (often similar to the original). Structural save options still run; the dramatic reductions typically appear on scan-heavy or photo-heavy PDFs.