PDF Merger
Merge PDFs in the browser. Files stay in the browser.
Secure PDF Merger
Combine multiple PDF files into a single document in this browser tab. Files stay in the browser. Drag files here or use the button.
Documents to Merge0 Files
No PDFs added yet.
Upload 2 or more files to start merging.
Build & Export
A PDF merger combines multiple PDF files into one document. This tool runs PDF-lib in the browser — files stay in the browser.
How to merge PDFs in the browser
- 1 Select your PDF files.
Click the Select PDFs button and choose two or more PDF files from your device. Files stay in the browser.
- 2 Reorder the files.
Use the up and down arrows next to each file to arrange them in the order you want in the merged document.
- 3 Merge the PDFs.
Click the Merge PDFs button. PDF-lib stitches the pages together in this browser tab.
- 4 Download the merged file.
Click Save Merged PDF to download the combined document. Your original files are unchanged.
The merge uses PDF-lib in this tab. Files stay in the browser.
Reorder files before you combine them
Use the up and down arrows next to each file so the top file is page 1 of the output. A contract, addendum, and fee schedule only make sense in that order — fixing order after you merge means splitting and starting over.
| File | Pages | Order in merge |
|---|---|---|
| cover-letter.pdf | 1 | 1st |
| service-agreement.pdf | 4 | 2nd |
| rate-schedule.pdf | 2 | 3rd |
| Merged output | 7 pages | One PDF |
What this tool does not upload
The selected PDFs are not posted to a merge API. PDF-lib reads them in this tab and writes the combined file for download. Files stay in the browser. That is not the same as a private or offline-only product — page views are still measured.
When a desktop app is still better
- Password-protected PDFs that must stay encrypted until you unlock them in a desktop app.
- Forms, complex bookmarks, or embedded JavaScript that PDF-lib may drop or flatten.
- Very large, image-heavy scans that exceed available browser memory.
- Workflows that need OCR, redaction, or certified signatures — use Adobe Acrobat, PDFsam, or a similar desktop tool.
For the PDF format itself, see Adobe's About PDF page (ISO 32000).
Frequently Asked Questions
What is a PDF merger? ▼
A PDF merger combines multiple PDF files into one document. This tool uses PDF-lib in the browser.
Does this tool upload my PDFs? ▼
The merge runs in the browser with PDF-lib. Files you select stay in the browser.
Is this PDF merger free? ▼
Yes. There is no account and no watermark on the merged file. The practical limit is your device's memory, not a billed upload quota.
What is the file size limit? ▼
There is no server-side file cap. The constraint is your device's available memory. Large scans or image-heavy PDFs can slow down or fail on low-RAM devices.
Will the merged PDF preserve bookmarks and form fields? ▼
Standard text, images, and page content are preserved. Interactive form fields, complex bookmarks, and embedded JavaScript may not merge correctly. For those files, a desktop app such as Adobe Acrobat or PDFsam is a better fit.
Can I reorder PDF files before merging? ▼
Yes. After adding files, use the up and down arrows next to each file to set the order. The top file becomes the first section of the merged document.
This tool is provided for informational and educational purposes only. Results are not a substitute for professional advice.
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