PDF Merger
Merge multiple PDF files into a single document.
How it works
- 1
Upload PDFs
Drag and drop or click to select the PDF files you want to merge.
- 2
Reorder files
Drag files to arrange them in the order you want.
- 3
Merge & download
Click "Merge & Download" to combine all files into one PDF.
Common use cases
Merge two reports
report-q1.pdf (12 pages) + report-q2.pdf (15 pages)
Combine scanned documents
scan-001.pdf + scan-002.pdf + scan-003.pdf
About This Tool
Upload multiple PDF files, drag to reorder them, and merge them into a single consolidated document — all processed entirely in your browser with no file uploads to any server.
Combining multiple PDF files into one is a common need in professional, academic, and personal workflows. Whether you are assembling a project report from chapters authored by different team members, merging scanned document pages into a single file, combining quarterly financial statements into an annual package, or simply joining downloaded invoices and receipts into one convenient file, a reliable PDF merger saves significant time and effort compared to alternatives like printing and re-scanning or purchasing desktop PDF software.
This tool provides a straightforward drag-and-drop interface for uploading, ordering, and merging PDF files. Start by dragging your PDF files onto the upload area or clicking to browse. Once uploaded, the files appear in a reorderable list — drag any file up or down to change its position in the final merged document. A progress indicator shows the merge status for larger operations, and the combined PDF downloads automatically when complete.
The merger uses the pdf-lib library, a pure JavaScript PDF manipulation library that runs entirely in your browser. It works by copying each page from each source PDF into a new blank PDF document in the order you specified. Page dimensions, orientation, text layers, embedded images, vector graphics, and fonts are preserved from the original files. The resulting merged document is a standard PDF that can be opened in any PDF reader, printed, shared, or further processed with other tools.
There is no hard limit on the number of files you can merge. Performance depends on the total number of pages and your device's available memory. Most users can comfortably merge 20 or more files containing hundreds of total pages without issues. For very large merges (thousands of pages), the browser may need additional time and memory, but modern devices handle this well.
The tool does not re-encode or recompress page content, so the merged PDF's file size is approximately the sum of the input file sizes. No quality is lost during the merge process. If you need to reduce the file size of the merged result, consider using a dedicated PDF compression tool.
For page-level operations — extracting specific pages, removing pages, or rearranging pages within a single PDF — use the PDF Page Extractor tool. The PDF Merger is designed for file-level operations: combining complete PDF documents. You can use both tools together: extract the pages you need from each source PDF, then merge the extracted results.
All processing happens in your browser using pdf-lib. Your PDF files are never uploaded to any server, never stored, and never accessible to third parties. This makes the tool safe for merging confidential documents, legal contracts, financial records, and any other sensitive PDF content.
More examples
Examples
Merge two reports
Input
report-q1.pdf (12 pages) + report-q2.pdf (15 pages)
Output
combined-report.pdf (27 pages)
Combine scanned documents
Input
scan-001.pdf + scan-002.pdf + scan-003.pdf
Output
all-scans.pdf with pages in upload order
Frequently Asked Questions
- Are my PDF files uploaded to a server?
- No. All merging happens in your browser using pdf-lib. Your files never leave your device.
- Is there a limit on the number of files?
- No hard limit. Performance depends on your device's memory. Most users can merge 20+ files with hundreds of pages without issues.
- Can I reorder pages from different PDFs?
- You can reorder the files before merging. For page-level rearrangement within or across files, use the PDF Page Extractor to extract specific pages first, then merge the results.
- Does merging preserve bookmarks and links?
- pdf-lib copies page content faithfully including text, images, and fonts. Internal bookmarks, annotations, and some interactive form fields may not transfer between documents.
- Is the merged PDF quality reduced?
- No. The tool copies page content without re-encoding or recompression. The merged PDF preserves the full quality of all source files.
- Can I merge password-protected PDFs?
- No. Password-protected or encrypted PDFs cannot be processed. Remove the password protection using the document owner password before uploading.
- How long does merging take?
- Most merges complete in seconds. Very large files or many pages may take longer depending on your device. A progress indicator shows the current status during processing.
- What is the maximum total file size?
- There is no enforced limit, but the total size of all files must fit within your browser's available memory. For most devices, merging files totaling up to 200 MB works smoothly.