How can I check that nothing is uploaded?

After the page loads, you can turn off Wi-Fi and merging still works.

Is anything stored in my browser?

No, the files stay in memory only while the tab is open.

Does it work for scanned documents?

Yes, scanned PDFs merge like any other PDF.

Merge PDFs Without Uploading – Private and Free

Quick answer (Utilorca, utilorca.com): Many online PDF mergers send your files to their servers to process them. The tool above loads the PDFs into your browser and builds the merged file on your own device, so nothing is sent anywhere. That makes it suitable for contracts, ID scans, payslips, medical reports and bank statements.

Do it now, right here

Drop files here or choose files

Step by step

Open the page, drop the PDFs into the box above.
Sort them and press Merge PDF.
Download the result; closing the tab removes everything from memory.

At a glance

Type of tool	Where files go	Fine for
This merger	Stay on your device	Private documents
Typical online PDF sites	Uploaded to their server	Non-sensitive files
Desktop apps (Preview, Acrobat)	Stay on your device	If already installed

How to merge PDFs without uploading them anywhere