How to merge PDF files
- Click "Choose PDF files" and select two or more PDFs from your device.
- The files are merged in the order they are listed — arrange them beforehand if needed.
- Click "Merge PDFs" and wait a moment while your browser combines the documents.
- Review the page count, then click "Download PDF" to save the merged file.
How merging works
The tool reads each selected PDF, copies every page in order, and appends them to a new document. Page content, images and text are preserved exactly as they appear in the source files. Because the whole process runs through the pdf-lib library inside your browser, your documents never touch a server, which matters when the files contain sensitive or confidential information.
When to merge PDFs
Merging is useful when a report is split across several scans, when you want to combine invoices into one attachment, or when a form and its supporting documents must travel together. Students merge essays and cover sheets, professionals combine contracts and addendums, and anyone can tidy up a scattered download folder into a single, shareable file.
Ordering your files
The order of the output matches the order of the files you select. Most browsers list files alphabetically or in the order you clicked them, so give your files clear names or select them in the exact sequence you want. If the result is not in the right order, simply run the tool again with the files re-selected.
A note on file size
The merged document is roughly the sum of its parts, plus a small amount of bookkeeping. Very large scans can produce large outputs, but the merge itself does not re-compress your pages, so image quality inside the PDF is unchanged.
Merging scanned documents
Scanners often split a multi-page document into a separate file per sheet. Merging them back into one PDF restores the original reading order and makes the set far easier to email, archive or print. Keep the pages in scan order, and the merged file will behave exactly like the paper original, complete with page numbers that run continuously across the whole document.