Compress PDF
Reduce PDF file size with lossless structural optimisation.
Overview
The Compress PDF tool reduces the file size of a PDF document by removing redundant data and applying efficient lossless compression to the document's internal structure (object and content streams). It does not re-encode or downsample images, so your text and images keep their original quality. The tool reports the exact before/after sizes and never returns a file larger than the original. This is useful for email attachments, web uploads, and reducing storage costs.
How to Use
- Navigate to Compress PDF from the Security & Optimization menu.
- Upload your file using drag-and-drop, Browse Files, or cloud storage (Dropbox / Google Drive).
- Select the compression level.
- Click Compress to process.
- Download the result when processing completes.
Options
| Option | Description |
|---|---|
| Compression level | Choose Light (lightest touch), Default (balanced), or Extreme (most optimisation passes). All levels are lossless — they differ only in how many structural optimisations are applied, not in image quality. |
Tips & Notes
Because every level is lossless, you can use Extreme for the smallest result without worrying about quality loss. Light is the quickest if you only need minor savings.
Compression is lossless and does not downsample images, so reductions depend on the PDF's internal structure. Text-heavy or already-optimised PDFs may compress only a little; documents with redundant or uncompressed structure benefit most. The result shows the real before/after size, and if a file can't be reduced the original is kept.
Related tools: Linearize PDF · Remove Blank Pages · PDF to Images