Merge PDF
Combine multiple PDF files into one single document instantly. All processing happens securely in your browser - no uploads, no servers, complete privacy guaranteed.
Selected Files:
Processing...
Next Steps: Perfect Your PDF Document
Perform more actions on your PDF files securely and offline.
Add Page Numbers
Easily paginate your PDF documents with custom page numbers. Perfect for merged files and long reports.
Reorder Pages
Organize and rearrange PDF pages exactly how you want them. Drag and drop to reorder without uploading.
Delete Pages
Remove specific pages from your PDF documents instantly. Keep only what you need, entirely offline.
Rotate PDF
Fix upset-down or sideways pages. Rotate individual pages or the entire document to the perfect angle.
Love using DumPDF? 🚀
Help us decide what to build next! Request features, report bugs, and chat with the dev on
Share this with your friends
Privacy Guaranteed
Your PDF files are processed entirely within your browser using client-side JavaScript. No data is uploaded to any server, ensuring complete privacy and security during the entire merging process.
Why Do You Need to Merge PDFs?
Merging PDF files is an essential productivity workflow. Whether you're combining several invoices into one monthly report, joining signed contract pages, or consolidating research into a single document, a reliable merger tool is a must-have. When you join PDFs into one file, they are significantly easier to store, print, and share over email without forcing recipients to download dozens of attachments. But remember to always merge them using a secure, client-side tool to avoid data leaks. Find out more about how to merge PDFs safely offline.
The Secure Way to Combine PDFs
Offline Merging
DumPDF runs entirely in your browser. Your confidential contracts and documents never leave your computer, making it much safer than cloud-based alternatives.
Unlimited Files
Merge as many PDF files as your browser memory allows. No artificial limits on file size or page count. If the final file grows too large, use our PDF Compressor afterwards.
Easy Reordering
Simply drag and drop your selected files to arrange them in the perfect order before combining them into a single document.
How to Merge PDF Files Securely
1. Select Your PDFs
Click 'Select PDF Files' or drag and drop multiple PDF documents into the upload area. You can add as many files as you need to combine.
2. Order Your Files
Once uploaded, simply drag and drop the file previews to arrange them in the desired order for your final merged document.
3. Merge & Save
Click the 'Merge & Save PDFs' button. The tool will instantly combine your files in your browser and save the new, single PDF to your device.
Frequently Asked Questions about Merging PDFs
Is it safe to combine confidential PDFs with this tool?
Yes, it is the safest method available. Since all files are processed locally on your computer, your confidential documents are never uploaded to a server. This guarantees your privacy when you join PDF files.
Is there a limit to how many PDF files I can merge at once?
Our tool is designed to handle a large number of files. While we recommend up to 20 files for optimal performance, the main limitation is your browser's memory. For most users, merging many files is fast and efficient.
Will merging PDFs reduce the quality of my documents?
No, our PDF merger securely combines documents without altering the visual quality of your original files. The content, formatting, and quality of each page will be preserved due to our direct offline structural manipulation.
What if I need to remove a page before merging?
If a document has a page you don't want to include, we recommend using our PDF Splitter or Delete PDF Pages tool to extract or remove that specific page first, then bring the clean document here to merge.
Can I reorder the PDF files before merging them?
Absolutely. After selecting your files, you can easily drag and drop them into the correct sequence. This ensures your final document is perfectly organized before you combine the PDFs.