Merge a group of PDF files to a single PDF file without disturbing the contents using PDFtk.

1. Merge and split PDF in PHP using PDFtk
Merge a group of PDF files to a single PDF file without disturbing the contents using PDFtk.
PDFtk runs on a variety of platforms, including: Windows, Linux, Mac OSX, FreeBSD and
Solaris.
It does not require Acrobat and allows you to manipulate PDF easily and freely.
What all you can do in PHP using PDFtk
Merge PDF documents to one.
Rotate PDF Pages or documents.
Split the pages of the PDF into a new document.
Encrypt the output as desired.
Decrypt the Input as necessary but requires password
Background watermark or a foreground stamp can be applied
Report on PDF metrics can be generated such as metadata, bookmarks, and page
labels.
Update PDF metadata.
Attach numerous files to the PDF document.
Compress a PDF document into a single page.
Under the GPL, PDFtk is licensed for the public.
Download Link: https://github.com/bensquire/php-pdtfk-toolkit
Examples:
You can provide two or more PDF files as arguments to create single PDF file as output.
Merge two or more PDFs into a new PDF file with all the original contents
pdftk example1.pdf example2.pdf example3.pdf cat output result.pdf
Rotate the first page of a PDF to 90 degrees clockwise
pdftk in.pdf cat 1E 2-end output out.pdf
Rotate all the pages of the PDF document by 180 degrees
pdftk in.pdf cat 1-endS output out.pdf
Report on PDF document metadata, bookmarks and page labels
pdftk mydoc.pdf dump_data output report.txt