How to Merge PDF Files Online
Merging is usually the last thing you do before sending something: an invoice plus a receipt, a form plus its supporting documents, or a set of scanned pages that arrived separately.
4 min readUpdated 14 September 2026Dockeazy editorial
The short answer
Open a merge tool, add your PDFs, drag them into the order you want, then merge and download. The order you set before merging is the order you get — most mistakes come from skipping that step.
Merge PDF
Combine multiple PDFs into one ordered document.
Step by step
- 1Add every file you want in the final documentSelect them all at once rather than one at a time. Files are listed in the order the browser hands them over, which is not always alphabetical.
- 2Put them in the right orderDrag each file into position. This is the step worth slowing down for, because reordering afterwards means opening the merged file in a separate tool.
- 3Decide whether you need compressionMerging does not shrink anything. If you are combining several scans, the result can be large enough to bounce off an email limit.
- 4Merge and check the resultOpen the downloaded file and scroll through it before sending. Page count is the quickest sanity check that nothing was dropped.
What merging does and does not change
Pages are copied into a new document exactly as they are. Text stays selectable, images keep their resolution, and nothing is re-encoded unless you deliberately choose a compression level.
What does not carry across reliably is anything that lives outside the page content: form fields may flatten, and bookmarks from the original files are not rebuilt in the merged document.
If one of your files is password-protected
A PDF that asks for a password before it opens cannot be merged while it is still locked. Remove the protection first with a tool you trust, then merge the unlocked copy.
If you do not know the password, there is no legitimate way around it. That protection exists precisely to stop the file being recombined by someone who should not have it.
Keeping the file small enough to email
Most mail providers reject attachments somewhere between 20 MB and 25 MB. Scanned pages are the usual culprit, because each page is a photograph rather than text.
Merging first and compressing second generally gives a better result than compressing each file separately, since the compressor can then treat the whole document consistently.
Frequently asked questions
Does merging reduce quality?
No. Pages are copied unchanged. Quality only changes if you separately choose to compress the merged file.
Can I merge more than two PDFs at once?
Yes. Add as many as you need in one go — the free plan covers up to 5 files and 50 pages per job, and Pro raises both limits.
Can I reorder pages rather than whole files?
Merge first, then open the result in the Organize PDF tool, where you can drag individual pages into any order.
Are my files uploaded to a server?
No. Merging runs inside your browser, so the documents never leave your device.
Related tools
Keep reading
Ready to try it?
Nothing to install and no account needed to start.
Open Merge PDF