Merge PDF Files Online: Combine PDFs in Any Order

How to merge PDF files

1. Click Browse Files or drop PDF files onto the box. Add files in one go or a few at a time.
2. Check the list. Files are merged from top to bottom; the number shows each file's position.
3. Drag a file, or use the ↑ and ↓ buttons, to change the order. Use × to remove a file.
4. Click Merge PDFs. The tool shows the number of pages and the final size, and downloads merged_document.pdf.

How PDF merging works

Each PDF is opened in your browser with the open-source pdf-lib library. Its pages are copied, in order, into a new empty PDF, together with the fonts and images they use. Nothing is re-rendered or re-compressed, so the result looks exactly like the originals.

Page count: pages in the merged file = the sum of pages in all files. Example: a 3-page UPSC application printout, a 1-page photo ID and a 6-page set of certificates give a 10-page PDF in exactly that order. If the three files are 450 KB, 120 KB and 1.2 MB, the merged file will be roughly 1.8 MB.

Tips

• Name files with numbers such as 01_form.pdf and 02_marksheet.pdf, so they sort in the right order when you add them.
• Keep the originals. Merging does not change your input files.
• Check the result in a PDF viewer before uploading it to an application portal.

Frequently Asked Questions

How do I merge PDF files into one?

Add two or more PDFs, arrange them in the order you want, and click Merge PDFs. The combined file downloads as merged_document.pdf, with every page of the first file followed by every page of the next.

How do I change the order of PDFs before merging?

Drag a file up or down in the list, or use the up and down arrow buttons next to it. The number in front of each file is its position in the merged PDF.

Can I merge password-protected PDFs?

Not directly. Open the protected PDF with its password, save or print it as a new PDF without a password, then add that copy here.

Is there a limit on the number or size of PDFs?

There is no fixed limit, because the merge runs on your own device. Very large files, such as several hundred MB in total, can run out of memory on a phone, so merge them in smaller groups.

Does merging reduce the quality of my PDF?

No. Pages are copied as they are, so text stays selectable and images keep their original resolution. The merged file is roughly the size of all the input files added together.

Are my PDFs uploaded to a server?

No. The pdf-lib library merges the files inside your browser, so your documents never leave your device.