Merge PDF
Combine multiple PDF files into one document directly in your browser. Add files, keep their order, and download a single merged PDF.
Input
Drop PDF files here
or click to browse multiple files
Settings
Files are merged in the order shown. Use the arrow controls to adjust the order before creating the final PDF.
How to merge PDF files
Add your files, put them in order, and download one combined PDF.
- 01
Add two or more PDFs
Drop them in together or one at a time. With only one file added, the tool asks you to add another before it merges.
- 02
Put them in order with Up and Down
Files are joined top to bottom. Use the Up and Down buttons next to each file to move it, and the X to take one out.
- 03
Merge and download
Every page of every file is copied into one new PDF, in the order shown. The original files aren't changed.
What the merge keeps, and what it doesn't
Merging uses pdf-lib to create an empty PDF and copy each source file's pages into it. A page's content comes across untouched: text stays selectable, scans keep their resolution and vector drawings stay sharp. Nothing is re-rendered, so the merged pages look exactly like the originals.
Document-level features are a different matter, because they belong to each original file rather than to its pages. Bookmarks and the table of contents panel aren't carried over. Fillable form fields may stop working or show their values as flat text. Digital signatures become invalid, because changing the file is exactly what a signature is meant to detect. If any of those matter, merge in Adobe Acrobat, or send the files separately.
How big the merged file will be
Expect the merged PDF to be close to the total of the files you added. The output is saved with object streams, a compact PDF structure, so it can come out a little smaller than the sum. But fonts and images are copied with each file's pages, so two documents that use the same font both bring their own copy. If a portal limits uploads to, say, 5 MB, add up your file sizes first, and run the result through PDF Compressor if it's over.
Fixing common merge problems
Most problems show up after the merge, when you flip through the result. These are the usual ones and what to do about them.
| What you see | Why | Fix |
|---|---|---|
| An error saying a file may be encrypted or damaged | It has an open password, or it's corrupted | Remove the password, or open it and re-save with Print › Save as PDF |
| Pages in the wrong order | Files merge top to bottom | Move files with Up and Down, then merge again |
| A mix of A4 and Letter pages, or some pages landscape | Each page keeps its original size and orientation | Expected; viewers show each page at its own size |
| A form that no longer fills in | Form fields belong to the original document | Fill and flatten forms before merging |
| A file too big to upload | Fonts and images are copied from every source | Run the result through PDF Compressor |
Common reasons to combine PDFs
A job application in one file
Join a cover letter, CV and certificates in the order the employer lists them, so the recruiter sees one tidy document.
Scans that came out page by page
Many scanner apps save each page as its own PDF. Merge them into a single document before you send it.
Reports with separate appendices
Put the cover, the main report and its appendices into one file for a client, even if each came from a different program.
Visa and loan paperwork
Applications often want ID, address proof and bank statements in a single upload. Keep confidential documents on your own device while you combine them.