Merge PDF — Combine PDF Files Online
Browser-based PDF merger with previews and drag-to-reorder, no upload
Runs in your browser · nothing is uploaded
Drop PDF files here
Add up to 50 PDFs, up to 100 MB each and 500 MB in total. Files never leave your browser.
What it is
A PDF merger joins several PDF files into a single one. It is handy when you need to send one file instead of five, when a scanner produced a separate PDF for each sheet, or when a cover page, the main text and an appendix live in different files. After you add files, each one appears as a card with a preview of its first page and its page count, and the order of the cards is the order of the merged result. Everything happens in your browser, so unlike merge sites that receive your files on a server, your documents stay on your device.
How to use
- Drop PDF files on the dashed area or press Choose PDFs. You can select several at once and add more later.
- Check the page counts and previews. A password-protected or damaged file shows a message on its card and is skipped.
- Drag cards to reorder them, or use the arrow buttons. Remove files you do not want with Remove.
- Press Merge PDFs. Progress is shown, and when it finishes you can download the PDF named after the first file with
-mergedadded (for examplequote-merged.pdf). Files that could not be read are counted and left out, and the page says so beforehand.
Rules and limits
- Counts and sizes: up to 50 files, 100 MB per file and 500 MB in total. Files that would pass the total are skipped with a notice.
- Detection: a file is accepted when it contains the
%PDF-marker, not because of its extension. A different file renamed to .pdf will not open. - What is copied: the content of every page (text, images, vector shapes) plus page size and rotation. Pages of different sizes keep their own size.
- What is not copied: bookmarks, document info such as the title, and the accessibility tag structure are not written to the new file. Annotations such as form fields and links may not be fully preserved.
- Encrypted files: password-protected PDFs are not supported. A scan-only PDF merges as it is, but no text recognition (OCR) is performed.
- Libraries: pdf-lib (MIT) writes the file and PDF.js (Apache-2.0) draws the previews. Both are downloaded only on the PDF pages.
Examples
| Situation | What to do |
|---|---|
| Cover, body and appendix in one file | Add them in order and merge |
| Several scanned sheets as one document | Check the file-name order, then merge |
| Insert one PDF into the middle of another | Cut the first PDF with Split PDF, then merge the pieces in the new order |
| Turn several images into one PDF | Create it with JPG to PDF first, then merge |
To fine-tune the page order after merging, use Organize PDF to drag, rotate or delete pages. To pull pages out instead, use Split PDF.
FAQ
Are my PDF files uploaded anywhere?
No. The whole merge runs inside your browser and the files are never sent to a server. That makes it suitable for contracts, invoices and other documents you would rather not hand to a third party. The result only exists on your device once you download it.
Can I merge password-protected PDFs?
Not yet. If you add a PDF that asks for a password to open, its card says so and the file is left out of the merge. Open it in a PDF viewer, remove the password, save a copy and add that copy instead. A PDF that opens without a password but has editing restrictions (security settings) cannot be used either; it gets its own message. Saving it again with Print → Save as PDF in a PDF viewer often works.
Do form fields and bookmarks survive the merge?
Not completely. The content drawn on each page (text, images, shapes) is copied as it is, but document-level bookmarks (the outline), document info and the tag structure are not carried into the new file. Annotations such as form fields and links may keep their look but stop being fillable, and links can break. Check the result if you rely on fillable forms.
Does it work with scanned or large PDFs?
Scanned PDFs hold one image per page, so they merge fine. The limits are 100 MB per file, 50 files and 500 MB in total, and the result is built in browser memory, so merging several very large files can be slow or fail. If that happens, merge in smaller groups.
How do I change the order?
Drag a card to a new spot, use the arrow buttons under it, or focus a card and press Alt with the arrow keys. The first card becomes the first pages of the result. Use the remove button to drop a file you do not need.
Related tools
Split PDF
Split a PDF by page ranges, every N pages or per page, with ZIP download, in the browser
Organize PDF
Reorder, rotate and delete PDF pages with thumbnails, in your browser
JPG to PDF
Combine several images into one PDF with paper size, margin and orientation, in the browser
PDF to JPG
Render PDF pages to JPG or PNG at a chosen DPI and download a ZIP, in the browser
Interleave PDF
Browser tool that alternates the pages of an odd-pages (fronts) PDF and an even-pages (backs) PDF