Two compression methods
Choose Safe when preservation matters
Safe compression keeps the PDF structure and cleans up its storage. Strong compression rebuilds pages as images, which can work well for scans but removes interactive document features.
Before you start
- Safe compression may have little effect or make an already optimized PDF slightly larger.
- Strong compression does not preserve searchable text, links, bookmarks, annotations, forms, layers, or attachments.
- Encrypted and digitally signed PDFs are blocked. Open important results and verify them yourself.
A practical example
Start with Safe for a report that needs searchable text or working links. For a scan, you can explicitly choose Strong when available and enter a target in KB or MB.
Check your result
Compare the original and result sizes, then zoom in on small text and stamps in the output. Strong prioritizes the visual result and removes document features such as searchable text, links, and forms.
Keep in mind for this task
- Target size applies only to Strong and is not guaranteed. An already optimized file may stay the same size or grow under Safe compression.
- On mobile devices, files trigger a warning at 20 MiB and are blocked at 50 MiB or above. Smaller files can still be limited by page dimensions or available device memory.