How to Merge PDF Files Online
Combining multiple PDF files into a single document is a common need. Whether you are assembling a report from several sections, combining invoices into one file, or putting together a collection of documents for review, a PDF merger saves you from manually copying and pasting between files.
This PDF merger combines multiple files into one document directly in your browser. Upload your files, arrange them in the order you want and download the merged result. Everything happens locally — your documents never leave your device.
How to Use This Tool
- Add files — click Choose files or drag multiple PDFs into the upload area.
- Arrange the order — use the arrow buttons to move files up or down in the list.
- Merge — click the Merge PDFs button to combine them.
- Download — save the merged PDF to your device.
- Start over — click Start over to merge a new set of files.
Arranging File Order
The order of files in the list determines the order of pages in the merged document. You can:
- Move a file up — click the up arrow to move it earlier in the sequence.
- Move a file down — click the down arrow to move it later in the sequence.
- Remove a file — click the X button to remove it from the merge.
The first file in the list becomes the first pages of the merged document, and so on.
What the Tool Shows
For each file you add, the tool displays:
- File name — so you can identify each document.
- File size — to help you stay within limits.
- Page count — so you know exactly how many pages each file contributes.
How Merging Works
The tool uses the pdf-lib library to copy pages from each source PDF into a new combined document. Pages are copied exactly as they are — no re-encoding, no quality loss. The result is a single PDF that contains all pages from all files in the order you specified.
Common Use Cases
- Combining chapters or sections of a report
- Merging invoices or receipts into one file
- Assembling a collection of documents for submission
- Joining related PDFs for easier navigation
Privacy
Your files are processed entirely in your browser. No PDF content is ever uploaded to a server. The merging happens using JavaScript and the pdf-lib library, keeping your documents completely private.