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pdf100% Browser-BasedUpdated Jul 2026

Merge PDF

A powerful, privacy-first PDF merging tool that works entirely in your browser. Upload multiple PDFs, preview every page, reorder and rotate pages visually, then merge them into a single document with one click. No file uploads. No servers. No tracking.

Your Files Never Leave Your Device

All PDF processing happens entirely in your browser using JavaScript. Your files are never uploaded to any server, stored in the cloud, or accessed by third parties.

Upload PDF Files

Drag & drop PDF files here, or click to browse. Multiple files supported.

Only PDF files are supported. Your files never leave your device.

About PDF Merging

Learn more about combining PDF files.

What is PDF Merging?

PDF merging is the process of combining multiple PDF files into a single document. This is useful when you have separate documents — like chapters of a report, scanned pages, or different versions of a contract — that you want to consolidate into one file for easier sharing, printing, or archiving.

When Should You Merge PDFs?

Merging PDFs is helpful in many scenarios: combining multiple scanned documents into one file, assembling project reports from different contributors, consolidating invoices or receipts, creating a single portfolio from multiple PDFs, merging presentation slides with supporting documents, and combining legal documents for court submissions.

Privacy Advantages of Browser-Based Processing

Unlike cloud-based PDF tools that require uploading your documents to external servers, browser-based PDF processing keeps your files completely private. Your sensitive documents — contracts, financial records, personal information — never leave your computer. There is no risk of data breaches, unauthorized access, or third-party storage. This is especially important for legal, medical, and financial documents.

Tips for Organizing Documents Before Merging

For best results, ensure all PDFs are in the correct reading orientation before uploading. Name your files descriptively so they are easy to identify in the merge queue. Check for duplicate pages before merging. If you're combining scanned documents, ensure they are all scanned at similar resolutions for a consistent look. Consider compressing large files before merging to reduce the final output size.

PDF Workspace

More PDF tools coming soon to ForgePlug.

Split PDF

Split PDF into separate pages

Compress PDF

Reduce PDF file size

Rotate PDF

Rotate PDF pages permanently

Extract Pages

Extract specific pages

Organize PDF

Rearrange, delete and rotate pages

Image to PDF

Coming Soon

Convert images to PDF

PDF to Image

Coming Soon

Convert PDF pages to images

Keyboard Shortcuts
Ctrl + EnterMerge PDFsCtrl + ZUndo last action

Frequently Asked Questions

How does browser-based PDF merging work?
PDF merging happens entirely in your browser using JavaScript. When you upload PDF files, they are read locally using the File API. The pdf-lib library processes and combines the pages into a single document. No data is ever sent to any server — your files remain on your device at all times.
Is my data safe when using this Merge PDF tool?
Yes, 100%. Your PDF files never leave your device. All processing happens locally in your browser using JavaScript. There are no file uploads, no server storage, and no third-party services involved. This is the most privacy-friendly way to merge PDFs.
What is the maximum file size I can merge?
The maximum file size depends on your browser's memory limits. In most modern browsers, you can comfortably merge files up to 100MB total. For very large PDFs, the browser may need more memory. If you experience performance issues, try merging fewer files at a time.
How many PDFs can I merge at once?
There is no hard limit, but we recommend merging up to 10-15 files at a time for optimal performance. You can always merge the resulting document with additional files if needed.
Can I reorder pages before merging?
Yes! You can reorder entire PDF files by dragging them up or down. You can also expand each file to see its individual pages and reorder pages within or between documents. This gives you complete control over the final document structure.
Can I rotate pages before merging?
Absolutely. You can rotate any page left or right before merging. This is useful for correcting scanned documents that were uploaded in the wrong orientation.
Will the merged PDF preserve bookmarks and metadata?
By default, page content is preserved with high fidelity. However, bookmarks, form fields, and some metadata may not survive the merge process due to limitations of browser-based PDF processing. We recommend keeping original copies of your files.
Does this tool work offline?
Once the page has loaded and the PDF library has been fetched, yes! The core merging functionality works even without an internet connection since all processing happens locally in your browser.
What happens to my files after I close the page?
Nothing. Your files are only stored in your browser's memory while the page is open. Once you close the tab or browser, all data is automatically cleared. We do not store, cache, or retain any copies of your files.
Can I preview pages before merging?
Yes! You can preview every page of each uploaded PDF as a thumbnail. This allows you to verify the content, check orientation, and decide which pages to include before merging.
How accurate is the estimated output size?
The estimated output size is a rough calculation based on the input file sizes. The actual output size depends on the complexity of the PDF content, embedded fonts, and images. The estimate is typically within 10-20% of the final size.
What makes ForgePlug's Merge PDF different from other tools?
Our Merge PDF tool is built as a complete PDF workspace, not just a simple merger. Features like visual page reordering, page rotation, live previews, drag-and-drop organization, and browser-only processing set it apart from traditional PDF merging tools. Plus, your files never leave your device.

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Frequently Asked Questions

Everything you need to know about merging PDFs

How does browser-based PDF merging work?
PDF merging happens entirely in your browser using JavaScript. When you upload PDF files, they are read locally using the File API. The pdf-lib library processes and combines the pages into a single document. No data is ever sent to any server — your files remain on your device at all times.
Is my data safe when using this Merge PDF tool?
Yes, 100%. Your PDF files never leave your device. All processing happens locally in your browser using JavaScript. There are no file uploads, no server storage, and no third-party services involved. This is the most privacy-friendly way to merge PDFs.
What is the maximum file size I can merge?
The maximum file size depends on your browser's memory limits. In most modern browsers, you can comfortably merge files up to 100MB total. For very large PDFs, the browser may need more memory. If you experience performance issues, try merging fewer files at a time.
How many PDFs can I merge at once?
There is no hard limit, but we recommend merging up to 10-15 files at a time for optimal performance. You can always merge the resulting document with additional files if needed.
Can I reorder pages before merging?
Yes! You can reorder entire PDF files by dragging them up or down. You can also expand each file to see its individual pages and reorder pages within or between documents. This gives you complete control over the final document structure.
Can I rotate pages before merging?
Absolutely. You can rotate any page left or right before merging. This is useful for correcting scanned documents that were uploaded in the wrong orientation.
Will the merged PDF preserve bookmarks and metadata?
By default, page content is preserved with high fidelity. However, bookmarks, form fields, and some metadata may not survive the merge process due to limitations of browser-based PDF processing. We recommend keeping original copies of your files.
Does this tool work offline?
Once the page has loaded and the PDF library has been fetched, yes! The core merging functionality works even without an internet connection since all processing happens locally in your browser.
What happens to my files after I close the page?
Nothing. Your files are only stored in your browser's memory while the page is open. Once you close the tab or browser, all data is automatically cleared. We do not store, cache, or retain any copies of your files.
Can I preview pages before merging?
Yes! You can preview every page of each uploaded PDF as a thumbnail. This allows you to verify the content, check orientation, and decide which pages to include before merging.
How accurate is the estimated output size?
The estimated output size is a rough calculation based on the input file sizes. The actual output size depends on the complexity of the PDF content, embedded fonts, and images. The estimate is typically within 10-20% of the final size.
What makes ForgePlug's Merge PDF different from other tools?
Our Merge PDF tool is built as a complete PDF workspace, not just a simple merger. Features like visual page reordering, page rotation, live previews, drag-and-drop organization, and browser-only processing set it apart from traditional PDF merging tools. Plus, your files never leave your device.

About Merging PDFs

A complete guide to merging PDF files.

What is PDF Merging?

PDF merging is the process of combining multiple PDF files into a single document. This is useful when you have separate documents — like chapters of a report, scanned pages, or different versions of a contract — that you want to consolidate into one file for easier sharing, printing, or archiving.

When Should You Merge PDFs?

Merging PDFs is helpful in many scenarios: combining multiple scanned documents into one file, assembling project reports from different contributors, consolidating invoices or receipts, creating a single portfolio from multiple PDFs, merging presentation slides with supporting documents, and combining legal documents for court submissions.

Privacy Advantages of Browser-Based Processing

Unlike cloud-based PDF tools that require uploading your documents to external servers, browser-based PDF processing keeps your files completely private. Your sensitive documents — contracts, financial records, personal information — never leave your computer. There is no risk of data breaches, unauthorized access, or third-party storage. This is especially important for legal, medical, and financial documents.

Tips for Organizing Documents Before Merging

For best results, ensure all PDFs are in the correct reading orientation before uploading. Name your files descriptively so they are easy to identify in the merge queue. Check for duplicate pages before merging. If you're combining scanned documents, ensure they are all scanned at similar resolutions for a consistent look. Consider compressing large files before merging to reduce the final output size.

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Runs in your browser100% privateNo data uploaded