When Do You Need to Merge PDFs?
Combining multiple PDF files is one of the most common PDF tasks. You might need to merge PDFs when:
- Combining chapters of a report or thesis into one document
- Attaching multiple invoices or receipts into a single file
- Merging scanned pages into one PDF
- Combining a CV with a cover letter
- Joining exported PDF reports from different software
How to Merge PDFs with OmniPDF
- Go to OmniPDF Merge PDF
- Click Upload PDFs and select multiple files, or drag & drop them all at once
- Drag to reorder the files if needed — the top file will be first in the merged PDF
- Click Merge PDFs
- Your combined PDF downloads immediately
Can I Choose the Page Order?
Yes! OmniPDF lets you drag and reorder files before merging. Each PDF's internal page order is preserved. You can also use our Page Organizer to rearrange individual pages after merging.
Tips for Merging PDFs
- Make sure all files are actually PDFs (not Word docs or images) before uploading
- If page sizes differ (e.g., A4 and Letter), the merged PDF will contain mixed sizes — this is normal
- For very large merges (50+ pages), use our Compress tool on the result to keep the file size manageable
Merge PDF vs Combine PDF — What's the Difference?
Nothing — they mean exactly the same thing. Both terms refer to joining multiple PDF files into one single document.
FAQ
How many PDFs can I merge at once?
Free users can merge up to 10 PDFs at once. Premium users have no limit.
Does merging reduce quality?
No. OmniPDF merges PDFs without re-rendering or re-compressing the content. Original quality is preserved perfectly.