Merge PDF Files

Merge multiple PDF files into one document online

Merge multiple PDF documents into a single file. Upload, reorder, and download your combined PDF instantly with no file size limits.

What is PDF Merger?

PDF Merger is a free online tool that allows you to combine multiple PDF documents into a single file. Whether you're organizing work documents, academic papers, or legal files, this tool makes merging PDFs simple and fast without complicated software.

Features

Merge Multiple PDFs: Combine up to 20 PDF files in one operation
Drag & Drop Reordering: Easily arrange files in any order using intuitive drag-and-drop interface
Preserve Quality: Maintains all original content, formatting, and quality during merging
No File Size Limits: Handle large PDF files (up to 50MB each) without restrictions
Instant Processing: Fast, browser-based merging with real-time progress tracking
Privacy Protected: All processing happens locally in your browser - nothing is uploaded
PDF Preview: Preview merged results before downloading
No Installation: Works directly in your web browser
No Registration: Completely free to use, no account needed
Batch Processing: Merge all files in one operation

How to Use

Step 1: Add PDF Files

Click the upload area or drag and drop your PDF files onto it
Select up to 20 PDF documents to merge (maximum 50MB per file)
Files are processed locally in your browser for complete privacy
You can add files one at a time or select multiple files together

Step 2: Arrange Files

Review all uploaded PDFs in a numbered list
Drag and Drop: Click and drag any PDF to reorder it
Arrow Buttons: Use up/down arrows for precise positioning
Remove: Click the trash icon to delete any PDF from the list
Clear All: Remove all files and start fresh
Files are merged in the exact order displayed

Step 3: Merge & Download

Click the "Merge PDFs" button to combine all selected files
Watch the progress bar as your PDFs are merged
Preview your merged PDF result
Click "Download Merged PDF" to save the file to your computer
Use "Merge Another" to combine additional PDFs without reloading

Perfect For

Business Documents: Combine reports, invoices, contracts, and receipts into organized files
Academic Work: Merge lecture notes, assignments, research papers, and study materials
Legal Documents: Combine contracts, agreements, supporting documents, and legal materials
Job Applications: Organize application materials, cover letters, and supporting documents
Presentations: Combine multiple presentation materials and related documentation
Book Compilation: Merge multiple document chapters into a single book
File Organization: Consolidate related PDFs into a single master document
Email Attachments: Create single files instead of multiple email attachments

Technical Details

Maximum Files: Up to 20 PDFs per merge operation
File Size: Up to 50MB per individual PDF file
Output Format: Standard PDF (fully compatible with all readers)
Processing: Real-time in your browser with progress tracking
Privacy: No uploads to external servers - all processing is local
Browser Support: Works on all modern browsers (Chrome, Firefox, Safari, Edge)
Performance: Fast merging even with large files
Smart Fallback: Automatically handles problematic PDFs by converting only affected files to images while preserving quality for valid PDFs

Tips for Best Results

Organize First: Arrange files in the correct order before merging - you can preview the order in the list
Check File Names: Use descriptive names to identify files during arrangement
Test with Samples: Start with smaller PDFs to familiarize yourself with the process
Keep Backups: Always maintain copies of your original PDFs
Preview Result: Review the merged PDF preview before downloading
Large Files: If handling very large files (40MB+), be patient during processing
Batch Operations: Merge up to 20 files at once for efficiency
Quality Preserved: All original content, formatting, and quality are maintained

Supported Formats

Input: PDF files (any PDF version)
Output: PDF (standard format compatible with all readers)
Maximum per merge: 20 PDF files

File Size & Performance

Per file limit: 50MB maximum
Total operation: Can merge files totaling 500MB+ (depending on browser memory)
Processing speed: Typically 1-5 seconds for standard merges
No automatic limits: Browser capacity may vary by device

Browser Compatibility

This tool works on all modern browsers:

Google Chrome/Chromium
Mozilla Firefox
Safari (Mac/iOS)
Microsoft Edge
Opera

Frequently Asked Questions

What does "Image-based" badge mean?

If you see an orange "Image-based" badge on your merged result, it means one or more of your PDF files couldn't be merged using the standard method. Don't worry - the tool automatically converted only the problematic pages to high-quality images (2x resolution) to ensure all content is preserved. Valid PDF files remain in their original quality with selectable text.

Why is my merged file larger than expected?

When the fallback method is used, pages converted to images typically result in larger file sizes compared to the original text-based PDFs. However, this ensures compatibility and preserves all visual content. Files that were successfully merged directly maintain their original size efficiency.

Can I still select text in the merged PDF?

Yes, for the pages that were merged directly without conversion. Pages that required image conversion won't have selectable text, but all visual content is preserved at high quality.

Privacy & Security

100% Private: Your PDF files never leave your browser
No Uploads: All processing happens locally on your device
No Tracking: We don't track your files or activities
No Storage: Files are not stored anywhere
Secure: Uses industry-standard PDF manipulation libraries
No Account Required: Completely anonymous usage

Credits

pdf-lib - Primary PDF manipulation library for fast, high-quality merging
PDF.js - Mozilla's PDF rendering library used for page counting and fallback processing when PDFs can't be merged directly

Privacy Notice: Your PDF files are never uploaded to our servers. All merging happens directly in your browser for complete security and privacy. The tool automatically selects the best method to handle your PDFs - most files are merged directly preserving full quality, while problematic PDFs are converted to images only when necessary.

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