Merge PDF
Drop in as many PDFs as you need, arrange them in order and export a single clean file. Great for contracts, reports and scanned bundles.
Private by design
Files are processed inside your browser and never uploaded anywhere.
No waiting
Results appear in seconds, with no queues or file size servers involved.
No sign-up
Use every tool as often as you like - no account, no watermarks.
Merging is the fastest way to turn a pile of separate documents - a signed contract, its annexes, a scanned ID and a receipt - into one file that can be filed or emailed as a single attachment. MobiPDF combines any number of PDFs in the exact order you arrange them, keeping each page at its original size and orientation. Because the merge happens in your browser, even confidential bundles stay on your computer.
How to merge PDF files
- 1Add two or more PDF files by dragging them in or browsing your device.
- 2Check the order of the list and remove or re-add files until the sequence is right.
- 3Run the merge and download the single combined PDF.
When to merge and what to expect
Merging is the right move whenever a recipient expects one document instead of a folder: tender submissions, expense claims, mortgage paperwork, assignment hand-ins or an invoice with its delivery notes attached. It is also the simplest way to rebuild a document that was scanned in several passes, because you can concatenate the batches instead of re-scanning.
The output keeps every source page exactly as it was - same dimensions, same rotation, same embedded fonts and images - so a mix of A4 text pages and landscape scans stays readable rather than being stretched to a common size. Nothing is re-encoded, which means no visible quality loss, and the final file size is roughly the sum of the inputs; run the merged file through Compress PDF afterwards if you need to fit an upload limit. Interactive form fields and annotations are carried over where the source files allow it, while bookmarks and internal links that pointed inside a single source document may not survive. Merging is done locally, so nothing is uploaded, no copy is retained on a server and the tool keeps working on a slow or offline-ish connection.
Frequently asked about Merge PDF
Can I control the order the documents appear in?
Yes. The merge follows the order of the file list, so arrange the list before running the tool. Removing a file and adding it again is the quickest way to move it to the end.
Is there a limit on how many PDFs I can merge?
There is no fixed limit - the practical ceiling is your device memory. Dozens of ordinary documents merge without trouble; very large scanned files are best merged in batches.
Will pages of different sizes be resized?
No. Each page keeps its original dimensions and rotation, so an A4 report merged with a landscape scan keeps both layouts intact.
Does merging reduce quality or make the file much bigger?
Quality is untouched because pages are copied, not re-encoded. The result is about as large as the inputs combined, so compress it afterwards if you have an email size limit.
What happens to form fields, links and bookmarks?
Form fields and annotations are carried over where the source PDFs allow it. Bookmarks and links that referenced positions inside an individual source file may be lost.
Can I merge a password-protected PDF?
Files with light restrictions usually merge fine, but a document that needs a password to open must be unlocked in your PDF reader and saved without encryption first.