The first goal of PDF merging is preserving page order. Bookmarks and outlines are extra PDF structures, and support varies by tool.
Recommended Workflow
- Name files in final reading order, such as 01-cover and 02-contract.
- Upload all PDFs and check page counts.
- Drag files into the correct order.
- Open the merged result and inspect the first page, last page, and chapter boundaries.
- If source PDFs have bookmarks, forms, or annotations, review them after export.
About Bookmark Preservation
Some PDF merge workflows copy page content but do not fully merge original outline trees, forms, actions, or complex interactions. For formal documents, always verify bookmarks after export.