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What structural compression changes
A structural optimizer saves the PDF with efficient object streams and may remove avoidable container overhead. Text, vector paths, page images, and interactive objects can remain in their original form.
This is the safer default for contracts, forms, accessible documents, and files that must remain searchable. It cannot guarantee a large reduction when embedded images already dominate the file.
What rasterization changes
Original pages
Text, vectors and images
Copy pages
Keep source objects intact
Merged PDF
New order, same page detail
Rasterization renders each page to a pixel canvas and encodes that canvas as an image. The new PDF can resemble the source visually while losing selectable text, vector sharpness, links, forms, layers, and accessibility tags.
Rendering detail and JPEG quality control the balance between size and visual fidelity. The best values depend on page content and output purpose.
Compare the two methods
Use the least destructive method that satisfies the actual delivery constraint. A dramatic size reduction is not useful if the document no longer supports its required workflow.
| Property | Structural optimization | Rasterization |
|---|---|---|
| Searchable text | Preserved | Usually lost |
| Vector sharpness | Preserved | Converted to pixels |
| Links and forms | Can remain interactive | Usually flattened |
| Image reduction | Limited | Controlled through re-rendering |
| Best use | Master-safe first pass | Reviewed delivery copy |
Choose by output purpose
Nexynto labels rasterized presets explicitly and keeps them separate from safe optimization.
- Use structural optimization for forms, contracts, searchable reports, and print masters.
- Consider rasterization for reviewed screen-delivery copies and image-heavy scans.
- Keep the original when choosing any lossy method.
- Run OCR afterward only when a rasterized copy must become searchable again.
Put the workflow into practice
Choose a compression method, preserve the original, and compare the measured result before using the new delivery copy.
Try Compress PDFFrequently asked questions
Clear answers before you compress
Is rasterization a type of compression?
It can reduce size, but it is a page conversion method with different functional trade-offs from structural compression.
Does rasterization flatten forms and links?
Yes, a page-image output generally loses interactive forms, links, layers, and selectable text.
Can OCR restore searchability?
OCR can add a new text layer, but recognition must be reviewed and does not recreate the original structure.
Which method should I try first?
Start with structural optimization when preserving document behavior matters, then consider a reviewed rasterized delivery copy if more reduction is required.