Why Merge PDF Files?
Combining multiple PDFs into one saves time and keeps documents organized. The key concern is how and where the merge happens — cloud vs local processing.
Local Merge vs Cloud Services
| Feature | Local Merge (Allin PDF) | Cloud Services |
|---|---|---|
| File Upload | No — in browser | Yes — uploaded |
| Privacy | Files never leave device | Stored on servers 1-24h |
| Speed | Instant (1-3 seconds) | Depends on upload speed |
| Bookmark Preservation | Yes | Varies |
| Offline | Yes | No |
Step-by-Step: Merge PDFs with Allin PDF
- Open the merge tool — No account needed.
- Add your files — Drag and drop multiple PDF files.
- Reorder pages — Drag into preferred order.
- Click Merge — Locally processed in 1-5 seconds.
- Download the result — Bookmarks and links preserved.
File Size Tip: When merging 10 PDFs totaling 45MB, the output is often 35-40MB because duplicate fonts are consolidated.
Preserving Bookmarks and Structure
- Retaining bookmarks from each source file
- Updating internal links
- Preserving form fields
- Maintaining metadata
FAQ
Limit on number of PDFs?
Up to 20 files in free tier. Practical limit depends on total file size (5MB free, 50MB Pro).
Will quality be reduced?
No. PDF merging is lossless — combines structures without re-encoding.
Can I merge password-protected PDFs?
Yes, after unlocking with the password first.