Merge PDF files online
Add two or more documents and merge PDF files into a single PDF in seconds, right in your browser.
Last updated
Your files never leave your device. Everything is processed in your browser and nothing is uploaded.
How to merge PDF files
- Press Choose PDF files and select two or more PDFs. You can add more files in several goes.
- Check the list: files are merged from top to bottom, and each file's page count is shown.
- Remove any file you added by mistake with its cross button.
- Press Merge PDFs, then Download merged.pdf to save the combined document.
How the PDF merger works
The merger uses pdf-lib, an open-source library for editing PDF files, running entirely in your browser. It opens each document you added, copies all of its pages and appends them to a brand-new PDF in the order of your list.
Pages are copied as they are, so text stays selectable and nothing is compressed again or turned into an image. Your files are never uploaded, which makes the tool safe for contracts, invoices and medical records.
The logic
Create an empty PDF. For each file in your list, load it, copy every page from the first to the last, and add the copies to the end of the new document. Save the result as merged.pdf.
The merged file's page count is always the sum of the page counts of the files you added.
Example
You have a 2-page cover letter, a 3-page CV and a 1-page certificate. Add them in that order and the merged PDF has 6 pages: pages 1 and 2 are the letter, pages 3 to 5 the CV, and page 6 the certificate.
If the three files are 120 KB, 300 KB and 80 KB, the merged file usually lands close to their 500 KB total, because each document brings its own fonts and images with it.
Tips and common mistakes
Add files in their final order
The list sets the page order. If a file ends up in the wrong place, remove it and add it again so it moves to the end.
Remove passwords before merging
Password-protected PDFs can't be combined. Open them in your PDF reader, enter the password and save an unprotected copy.
Turn photos into PDF pages first
Got a receipt or ID card as a photo? Convert the JPG to PDF, then merge it with the rest of your documents.
Share single pages as pictures
To post one page in a chat app, convert the merged PDF to JPG images after you download it.
Mind the upload limit
Many application portals cap files at a few megabytes. Scanned pages are usually what makes a PDF big, so compress the scan images before turning them into PDF pages.
Frequently asked questions
Are my PDFs uploaded to a server?
No. Files are combined in your browser and never leave your device.
How many PDFs can I merge?
As many as your device's memory allows. Dozens of ordinary documents work well; very large scanned files can be slow on phones.
Will the merged PDF keep its text?
Yes. Pages are copied without changes, so text stays selectable and searchable. Bookmarks and fillable form fields from the original files may not carry over.
Can I merge password-protected PDFs?
No. Remove the password in your PDF reader, save an unprotected copy and merge that instead.
Is a watermark added?
No. The merged file contains only your own pages.