# About the PDF Optimization Plug-in

The PDF optimization plug-in optimizes PDF document selected in the workspace.
When you optimize the PDF document, the hidden edit history data (pages, annotations, and document attributes) that is retained in the file is deleted, and the file size becomes small.*
*: These do not apply to PDF documents containing objects (tags, bookmarks, annotations and others) that refer to edit history data.

### Target PDF documents for optimization

PDF documents that can be optimized by using the PDF Optimization plug-in are:

- The PDF documents of version 1.3 to 1.7
- The PDF documents on which securities or digital signature are set
- Documents that do not have PDF/A attributes

### The optimized PDF documents

- The data in the original PDF document is not changed and is inherited.
- The PDF version after optimization will not be changed.