PDF Compressor uses pdf-lib to rebuild a PDF with structural optimizations: removing redundant cross-reference streams and normalizing the object layout. This can reduce file size for PDFs with inflated structure. Note: image content is not re-encoded, so image-heavy PDFs may see minimal reduction.
This tool applies structural compression by removing redundant cross-reference streams and optimizing the PDF object layout. It does not re-encode or discard images. For significant file size reduction, image re-encoding is required — which cannot be done safely in the browser without potentially altering image quality.
If a PDF is already efficiently structured or its size is dominated by images, structural compression will have little effect. Re-encoding images — which this tool intentionally does not do — is the main way to shrink image-heavy PDFs.
No. Structural compression removes overhead data only — redundant cross-reference streams and object layout bloat. Page content, fonts, and images are preserved exactly as in the original.
PDFs created or repeatedly edited by certain software often accumulate redundant objects and incremental update data. Those tend to see the biggest reduction from structural compression.
We'd rather be upfront: structural compression alone won't shrink image-heavy PDFs much. If you need real size reduction for scanned or photo-heavy PDFs, you'd need image re-encoding, which isn't what this tool does.
Not currently on this site. For image-heavy PDFs, consider extracting images, compressing them with Image Optimizer, and rebuilding the PDF.
No. Text remains fully selectable and searchable since the underlying text objects and fonts are untouched.
Yes, but if the file was already optimized (by this tool or another), running it again typically yields little to no further reduction.
