How to use the Merge PDF
- Drop your PDF files onto the box or click it to choose them. You can select many files at once.
- Check the page count shown for each file, then drag the files by their handle (or use the arrow buttons) to put them in the right order.
- Optionally type a name for the combined file, or use Sort A–Z if your files are numbered.
- Click Merge PDFs. The combined document downloads straight away.
Features
- Merge any number of PDFs, with page counts and first-page previews
- Drag-and-drop ordering that also works with a finger on phones
- Pages are copied exactly: no re-compression, text stays selectable
- Natural A–Z sorting, so “file 2” comes before “file 10”
- Clear message for damaged or password-protected files
- Runs entirely in your browser with no upload and no watermark
When merging PDFs saves time
Many forms and portals accept only one attachment, yet the documents you need usually arrive as separate files: a signed application, a scanned ID, two bank statements and a cover letter. Merging them gives the reader one file to open, one file to print and one place to search. It is just as useful for your own records, such as combining a year of monthly invoices or the chapters of a thesis written in separate files.
How this PDF merger works
A PDF is a collection of page objects plus the fonts, images and drawing instructions those pages use. When you click Merge, the tool reads each file with the open-source pdf-lib library, copies every page together with the resources it depends on, and writes them into a brand-new document in the order shown in the list. Because pages are copied rather than re-rendered, nothing is re-compressed: text stays sharp and selectable, vector drawings stay vector, and photos keep their original quality. The work happens in your browser’s memory, so confidential files never travel to a server.
What carries over, and what does not
| Item | In the merged PDF? |
|---|---|
| Page content, fonts and images | Yes, unchanged |
| Page size and orientation | Yes, each page keeps its own size |
| Links and comments placed on pages | Usually yes |
| Bookmarks (the outline panel) | No, the new file starts without bookmarks |
| Fillable form fields | May stop being editable; fill forms before merging |
| Title, author and other properties | No, set them afterwards with the PDF Metadata Editor |
Getting the order right
The list is the order of the final document, top to bottom. If your files are numbered, Sort A–Z uses natural ordering, so “scan 2.pdf” sorts before “scan 10.pdf”, which plain alphabetical sorting gets wrong. To change the order of individual pages rather than whole files, merge first and then open the result in Organize PDF, where you can drag single pages, rotate them or remove blanks.
Tips and common mistakes
- Password-protected files cannot be merged. Encrypted PDFs must be unlocked in a reader that knows the password before their pages can be copied. The tool tells you which file is protected instead of producing a broken result.
- Merged scans can be large. The output is roughly the sum of the inputs. If a portal has an upload limit, run the result through Compress PDF.
- Sideways pages stay sideways. Fix them before or after merging with Rotate PDF.
- Need only part of a file? Pull out the pages you want with Extract PDF Pages first, then merge the extracts.
Very large batches are limited only by your device’s memory. On a phone, merging a few hundred pages is usually fine; for thousands of scanned pages, a desktop browser is more comfortable.
Frequently asked questions
Is it safe to merge confidential PDFs here?
Yes. The files are read and combined inside your browser and are never uploaded, so contracts, statements and ID scans stay on your device.
Does merging reduce the quality of my PDFs?
No. Pages are copied as they are, without re-compressing images or converting text, so the merged file looks exactly like the originals.
How many PDF files can I merge at once?
There is no fixed limit. You can add files in several batches, and the only constraint is the memory of your device.
Why can’t I merge a password-protected PDF?
Encrypted PDFs cannot be read without their password. Open the file in a PDF reader, remove the protection or print it to a new PDF, and then add the unlocked copy.
Can I reorder single pages instead of whole files?
Merge the files first, then open the merged PDF in Organize PDF to drag individual pages into place, rotate them or delete the ones you do not need.