Merge PDF Files
Combine PDFs in any order.
- Files stay on your device
- No upload, no waiting
- No sign-up, no watermark
How it works
Add your PDFs
Drag your files onto the drop zone or click to browse. Select as many as you need.
Put them in order
Drag the file cards to reorder them. The merged document follows the order shown.
Merge and download
Press Merge. The combined PDF is built on your device and downloads immediately.
Questions
Are my PDFs uploaded to a server?
No. The merge runs entirely inside your browser using your own device's processor, so your documents never travel over the network. That matters for contracts, medical records, tax filings and anything else you would hesitate to hand to a stranger's server — and it means there is no upload wait and nothing for us to store or leak.
Is there a limit on file size or number of files?
There is no artificial cap. The practical ceiling is your device's available memory, since the whole document is assembled in RAM. Merging a few hundred pages is routine on any modern phone or laptop. Very large scanned files — hundreds of megabytes of images — may be slow on older mobile devices.
Will merging reduce the quality of my PDFs?
No. Pages are copied across byte-for-byte, with their original fonts, vector artwork and image resolution intact. Merging is a structural operation, not a re-encode, so nothing is recompressed and nothing is lost. The output size is roughly the sum of the inputs, minus some shared resources.
What happens to bookmarks, form fields and annotations?
Annotations, links and page-level content carry across. Document-level structures are trickier: interactive form fields are preserved but may collide if two files use the same field names, and top-level bookmark trees from the individual files are not merged into a single outline. Flatten forms before merging if exact fidelity matters.
Can I merge password-protected PDFs?
Not directly. A PDF with an open password has to be decrypted before its pages can be read, so remove the password in your PDF reader first, then merge. Files that are merely restricted from printing or editing — with an owner password but no open password — usually merge without any trouble.
About merge pdf
Why merging in the browser matters
Most online PDF tools work by uploading your document to a server, processing it there, and giving you a link to download the result. That is a reasonable engineering choice, and it is also the reason your employer’s IT policy probably forbids using them. The documents people most often need to merge — signed contracts, bank statements, medical records, tax packages, tenancy agreements — are exactly the documents you should not be handing to an unfamiliar server.
This tool never sends your files anywhere. The merge is performed by JavaScript running on your own device, using the same processor that opened the page. There is no upload progress bar because there is no upload, no size ceiling imposed by a free tier, and nothing sitting in a temporary directory afterwards waiting to be garbage-collected — or breached.
What is actually preserved
Merging is a structural operation, not a re-encode. Pages are copied across with their original content streams intact, so text stays selectable, vector artwork stays sharp, embedded fonts come along, and images are never recompressed. The output is roughly the sum of the inputs.
| Element | Preserved? | Notes |
|---|---|---|
| Text, fonts and vector graphics | Yes | Copied byte-for-byte; no re-encoding at any point |
| Images | Yes | Original resolution and compression are untouched |
| Page size and orientation | Yes | Mixed A4 and Letter pages stay at their own sizes |
| Links and annotations | Yes | Page-level annotations carry across |
| Form fields | Mostly | Fields survive, but identical field names across files can collide |
| Bookmarks / outline | No | Top-level outlines are not combined into a single tree |
| Encryption | No | Remove any open password before merging |
If exact fidelity of an interactive form matters, flatten it first — printing to PDF from your reader converts fields into static page content and removes any chance of a name collision.
Getting the order right
The merged document follows the order shown in the list, top to bottom, and you can move any file with the arrow buttons. This is worth a moment’s attention, because operating systems sort filenames as text rather than as numbers: page10.pdf sorts before page2.pdf. If you are merging scanned pages, either check the order here or rename the source files with zero-padded numbers — page02.pdf, page10.pdf — before you start.
Practical limits
There is no artificial cap on file count or size, but the whole document is assembled in memory, so your device’s available RAM is the real ceiling. A few hundred text pages is unremarkable on any modern phone. Several hundred megabytes of high-resolution scans will be noticeably slower on an older mobile device, and may run out of memory on a low-end one — merge in batches if you hit that.
Related
Browse the rest of the PDF tools, or head back to all tools.