Merging PDFs is useful in many situations: combining chapters into one document, attaching multiple forms to an application, or assembling a report from several separate files. Here is how to do it cleanly.
When You Need to Merge PDFs
- Sending multiple documents as one email attachment
- Binding contracts, appendices, and exhibits into one file
- Collecting pages from different scans into a single document
- Assembling presentation materials from multiple sources
How to Merge PDFs with ToolzStack
PDF Merge combines your files in the browser — nothing is uploaded to a server.
Steps:
- Go to PDF Merge
- Click Add files or drag and drop your PDFs
- Drag to reorder files if the sequence matters
- Click Merge and download the combined PDF
The output file will contain all pages from all input files in the order you arranged them.
Getting the Order Right
The order of files in the merge tool becomes the order of pages in the output. Take a moment to arrange them correctly before merging:
- Place the cover or title page PDF first
- Append supplementary materials, appendices, and exhibits last
- For documents with logical sections, merge in reading order
Handling Large Files Before Merging
If your individual PDFs are very large, consider compressing them first before merging. Merging large, unoptimised PDFs simply produces an even larger combined file.
A practical workflow for size-conscious merging:
- Compress each PDF individually
- Verify the compressed versions look correct
- Merge the compressed files
Things to Check After Merging
Page numbers: If individual documents had page numbers printed in the content, they will not automatically renumber. You may need to update numbering in a PDF editor or re-export from source if consistent pagination matters.
Bookmarks: If the original PDFs had bookmark navigation (a clickable table of contents), these may or may not carry through depending on the merge tool. For document-level navigation, consider using Organize PDF to add structure after merging.
File size: Check the merged file size. If it is unreasonably large, compress the merged output.
Alternative: Split and Re-merge for Precise Control
If you need specific pages from different PDFs (not entire files), use PDF Split to extract the pages you want first, then merge the extracted pages.
Related guides: How to Split a PDF Into Separate Pages