Merge PDF files
Drop two or more PDFs below, put them in order, and download a single combined file. Everything happens in your browser’s memory — the files are never uploaded, which is why this works offline and why there’s no file-size “premium tier”: your own computer is doing the work.
If you’re combining the front and back passes of a single-sided scanner, use the alternate & mix option that appears when exactly two files are loaded — it interleaves page 1, page 1, page 2, page 2… and can walk the second file backwards, which is the order most second passes come out in.
Drop your PDFs here
Add two or more files — or click to browse. Processed on your device, never uploaded.
How it works
- Drop your PDFs into the box above (or click to browse). Add as many as you need.
- Arrange them with the ↑ ↓ buttons — the merged file follows this order top to bottom.
- Click “Merge PDFs”. The combining happens on your device; nothing is sent anywhere.
- Download the merged file. The originals on your disk are untouched.
What survives a merge — and what doesn’t
Merging copies pages with their full contents: text stays selectable, links inside a page keep working, and scanned images keep their original resolution — pages are never re-rasterized, so there’s no quality loss.
Two honest caveats. Bookmarks (the outline panel in a PDF reader) are not carried over, because each source file’s outline points at its own page tree. And fillable form fields usually keep their appearance but can lose interactivity when two forms with clashing field names land in one file. If you’re merging filled forms for submission somewhere official, flatten them first — many courts and agencies require it anyway.
Good to know
- Password-protected files can’t be merged — remove the password first (open the PDF, enter the password, print to PDF). The tool will tell you honestly instead of producing a broken file.
- Merging very large scans? The whole job runs in your tab’s memory. A few hundred MB is fine on a normal laptop; multi-GB scans are not.
Frequently asked questions
Is there a limit on how many PDFs I can merge?
No hard limit — the practical limit is your device’s memory, since the merge runs locally. Dozens of ordinary documents are no problem. If your browser tab runs out of memory on an enormous batch, merge in two rounds.
Does merging reduce quality?
No. Pages are copied, not re-rendered — text, vector graphics and images pass through byte-for-byte. The merged file is roughly the sum of its parts.
Why do you not upload my files like other merge sites?
Because it isn’t necessary — browsers can do this work themselves. Uploading means your documents sit on someone’s server, subject to their retention policy. Here the “server” is your own device; open DevTools → Network while merging and you’ll see nothing leaves the page.
Can I mix page sizes and orientations?
Yes. Each page keeps its own size and orientation in the merged file, exactly as PDF readers expect. If something ends up sideways, fix it afterwards with the rotate tool.