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Merge PDFs
Combine multiple PDFs into one
Try Merge PDFs Online
Real Browser ProcessingNo files selected
All PDF processing runs in-browser. Security tools use a local encrypted container format for password workflows.
Merge PDFs combines multiple PDF documents into a single file — reports, invoices, scanned pages, chapters — in the order you choose. Everything happens on your device, so confidential documents are never uploaded.
Combine two files or fifty. The result is one continuous PDF you can then reorder, split, number or compress with the other PDF tools.
How To Use Merge PDFs Offline
- Open Merge PDFs — Find it under PDF Tools, or search "merge" with ⌘/Ctrl+K.
- Drop the PDFs in order — Drag all the files in — they merge in the order you added them. Add a cover page first if you have one.
- Process — One click produces the combined PDF in your output folder (~/Documents/1FileTool by default).
- Follow up if needed — Use Reorder Pages to fix page order, Page Numbers to stamp numbering, or Compress to shrink the merged file.
Why Use 1FileTool Over Online Tools?
- 100% offline — Files never leave your computer. No uploads, ever.
- Pay once — One-time payment from $29. No monthly subscriptions.
- Instant results — Local processing is faster than uploading + server processing + downloading.
- No file size limits — Process files of any size, limited only by your disk space.
- GDPR compliant — No data collection means complete privacy compliance by design.
Formats
| Input | Output | Notes |
|---|---|---|
| .pdf ×2 or more | Pages are concatenated in the order you drop the files. |
Good to know
- Merging preserves each document as-is — it does not reflow, resize or normalize page sizes.
- Replace source is ON by default; with it on, the merged file may overwrite a source — check Settings › General first.
- The free plan processes 8 files per calendar day.
Tips
- Name files 01-contract.pdf, 02-appendix.pdf so dropping them keeps the right order.
- Merge first, then compress once — compressing a merged PDF beats compressing the parts.
- Mixing portrait and landscape pages is fine; each page keeps its own size and rotation.
Frequently asked questions
Does merging change page content?
No. Pages are combined unchanged — fonts, images, links and forms survive. Only the page order is what you control.
How many PDFs can I merge?
There is no fixed cap — drop as many as you need. Batch jobs run with a progress bar and cancel.
Can I reorder pages after merging?
Yes — use the Reorder Pages or Duplicate Pages tools, or the visual PDF Editor for drag-and-drop page management.
Are my documents uploaded?
No — merging runs locally with the bundled pdf-lib engine. Nothing leaves your computer.