Merge PDF
Combine multiple PDFs into one document
Drop PDF files here or click to browse
Add multiple PDFs to merge them into one
Merge PDF files online for free
Combining multiple PDF documents into a single file is one of the most common PDF tasks. Whether you need to merge invoices for bookkeeping, compile research papers into a single reference, or put together a proposal from separate sections, OpenPDF's merge tool handles it effortlessly.
Simply drag and drop your PDF files into the upload area above. You can add as many documents as you need — there are no file count limits. Once your files are loaded, use the arrow buttons to reorder them in the exact sequence you want. The merge follows the order shown in the list from top to bottom.
All processing happens directly in your browser using JavaScript and WebAssembly. Your files are never uploaded to any server, which means complete privacy and fast processing regardless of your internet connection. This makes OpenPDF particularly useful for handling confidential business documents, legal contracts, and personal financial records.
The merged PDF preserves the original formatting, fonts, images, and interactive elements from each source file. Links, form fields, and bookmarks are maintained in the combined document. After merging, the file downloads automatically — no extra steps required.
OpenPDF works on all modern browsers including Chrome, Firefox, Safari, and Edge. It is fully responsive and works on mobile devices as well, so you can merge PDFs from your phone or tablet when you are on the go.
Frequently asked questions
How many PDFs can I merge at once?
There is no hard limit on the number of files. Since everything processes locally, performance depends on your device. Most users can merge dozens of files without issues.
Will merging change the quality of my PDFs?
No. The merge process copies pages exactly as they are. All text, images, vectors, and formatting remain identical to the originals.
Can I reorder the pages before merging?
Yes. Use the up and down arrows next to each file to change the order. The final merged document follows the order shown in the list.
Is there a file size limit?
There are no server-imposed limits. Your browser handles the processing, so very large files (over 100 MB each) may be slower depending on your device.
Are my files uploaded to a server?
No. All processing happens in your browser. Your files never leave your device, and we have no access to them.