Best way to merge 2 pdf files

Aspose.PDF Product Family
1

We have 2 pdf files one with 10 pages and the other with 25,000 pages. What is an effective method to merge the 2 files?

We want 10 pages file to appear first and then file with 25,000 pages.

2

@swapnilyadav

The recommended approach is to use DOM as following:

Document doc1 = new Document("10Pages.pdf");
Document doc2 = new Document("2500Pages.pdf");
doc1.Pages.Add(doc2.Pages);
doc1.Save("resultant.pdf");

Furthermore, following documentation article(s) offers more information about PDF Document Concatenation: