Merge PDF
Add two or more PDFs, put them in the order you want, and save them as a single document. Every page is copied over unchanged.
Done.
Your PDFs are read and merged inside your browser. They are not uploaded to our server.
How to use the Merge PDF
- Drop your PDF files onto the box above, or click it to pick them. You can add files in several batches; each new batch goes to the end of the list.
- Check the order. Use the ↑ and ↓ buttons to move a file up or down, and ✕ to take it out. The pages of file 1 come first in the result.
- Press Merge PDFs. The page count and size of the new file appear when it is ready.
- Change the file name if you like, then press Download merged PDF.
What happens to your pages
The tool uses the open-source pdf-lib library to open each file and copy its pages, in order, into a brand-new PDF. Pages are copied as they are, not re-rendered, so text stays selectable and searchable, images keep their original quality, and page sizes are kept. A letter-size file merged with an A4 file gives a document with both page sizes in it.
Because nothing is recompressed, the merged file is usually close to the combined size of the inputs. If the result is too big to email, run it through the Compress PDF tool afterwards.
What is not carried over
- Bookmarks (the outline panel in a PDF reader) are not copied into the merged file.
- Fillable form fields may look right but stop working as fields, because the form definition belongs to the original document rather than to its pages.
- Links that jump to another page inside the same document may stop working. Links to websites normally keep working.
- Encrypted PDFs, including files that open without a password but restrict editing or printing, cannot be read by pdf-lib. Remove the protection in the program that created the file, then try again.
Tips
To merge only part of a file, cut out the pages you need first with Split PDF, then merge the pieces. To include a Word document, convert it with Word to PDF first. Very large files are limited by your device's memory; if a merge fails on a phone, try it on a computer.
Frequently asked questions
Are my PDFs uploaded anywhere?
No. The files are read by JavaScript in this browser tab and the merged PDF is built there too. The only thing downloaded from the internet is the pdf-lib library itself.
Is there a limit on the number of files or pages?
There is no fixed limit in the tool. The practical limit is your device's memory, because every file is held in memory while the new document is built.
Can I merge password-protected PDFs?
No. pdf-lib cannot decrypt files, so encrypted PDFs are flagged in the list and skipped. Open the file in a program that knows the password, save an unprotected copy, and add that instead.
Will the quality of my PDFs change?
No. Pages are copied rather than converted, so text, vector graphics and images are exactly as they were in the source files.
Can I reorder individual pages, not just whole files?
Not in this tool, which keeps each file's pages together. Split the files into the pieces you need with Split PDF, then add the pieces here in the order you want.