How to Merge PDF Files Online
- Drag and drop your PDF files into the box above, or click to browse.
- Arrange files in the order you want using the up/down arrows.
- Click "Merge" — your combined PDF downloads instantly.
All processing happens in your browser — your files are never uploaded to any server, keeping your documents completely private and secure.
Why Use JustPDF to Merge PDFs?
Unlike other online PDF mergers that upload your files to remote servers, JustPDF processes everything locally on your device. This means your confidential documents, contracts, and personal files stay private. There are no file size limits on individual PDFs, and you can merge up to 20 files at once.
Common Use Cases
- Combine multiple scanned pages into a single document
- Merge separate chapters or sections into one report
- Join invoice PDFs for accounting and record-keeping
- Consolidate signed contracts and agreements
Frequently Asked Questions
Is there a file size limit?
There's no strict limit — since processing happens in your browser, it depends on your device's memory. Most users can merge files up to 100MB+ without issues.
Will the merged PDF lose quality?
No. JustPDF combines your PDFs exactly as they are, with no re-compression or quality loss.
Can I reorder pages after merging?
You can arrange the order of entire files before merging. For page-level reordering, use our Split tool to extract specific pages, then merge them in your desired order.