PDF Merger Online Tool

Combine multiple PDF files into a single document with our free online tool. Supports up to 10 PDF files with instant merging.

Upload PDF Files

Drag & drop PDF files here or click to browse

Supports multiple PDFs (max 10 files, 100MB total)

Merge Results

PDFs merged successfully!
0
Files Merged
0 KB
Total Input Size
0 KB
Merged File Size
0%
Size Efficiency
Download Merged PDF

Merged PDF will appear here

How to Use This PDF Merger Tool

Merging PDF Files

  1. Upload PDF files using either:
    • Drag and drop multiple files into the upload area
    • Click to browse and select multiple files
    • Upload files one by one
  2. Review file list and remove any unwanted files
  3. Click "Merge PDFs" button to combine files
  4. View merge results
    • File count and sizes displayed
    • Merging efficiency shown
  5. Download merged PDF using the download button

PDF Merging Features

Multi-File
Merge 2-10 PDF files
PDF Only
PDF format validation
Size Efficient
Optimized merging
Secure
Server-side processing
  • Order preservation: Files are merged in upload order
  • Page integrity: All pages from each PDF are included
  • Fast processing: Server-side merging for speed

Technical Specifications

File Requirements

  • Format: PDF files only
  • Count: 2-10 files per merge
  • Size limit: 100MB total input size
  • Validation: Automatic PDF format checking

Processing Details

  • Engine: Apache PDFBox library
  • Method: Page-by-page merging
  • Output: Single consolidated PDF
  • Quality: Original quality preserved

Important Notes

  • Order matters: Files are merged in the order they appear in the list
  • File validation: Only valid PDF files are accepted
  • Size limits: Large files may take longer to process
  • Privacy: Files are processed server-side and temporary files are cleaned up

Frequently Asked Questions

You can merge between 2 and 10 PDF files in a single operation. This limit ensures optimal performance and prevents server overload.

PDFs are merged in the order they appear in your file list. You can reorder files by removing and re-uploading them in the desired sequence.

Yes, your files are processed securely. Uploaded PDFs are temporarily stored on the server only for processing and are automatically deleted after 30 minutes. The merging process happens server-side using industry-standard PDF libraries.

PDF merging optimizes the file structure by consolidating shared resources (fonts, images, etc.) across documents. This can sometimes result in a smaller merged file than the sum of individual file sizes, or occasionally larger due to metadata consolidation.