In what order are the PDFs combined?

In the order you add them, top to bottom. Drag and drop the files in the list to reorder before merging.

Are my PDFs uploaded anywhere?

No. The merge happens entirely in your browser, so your files never leave your device.

No fixed limit. You can combine as many PDFs as you like, though very large files may take longer since your device does all the processing.

Combine multiple PDF files into one. Free and private. Everything runs in your browser; your files are never uploaded.

Combine multiple PDFs, like scanned receipts, contract pages, or chapter files, into a single ordered document without installing anything.

In what order are the PDFs combined?: In the order you add them, top to bottom. Drag and drop the files in the list to reorder before merging.
Are my PDFs uploaded anywhere?: No. The merge happens entirely in your browser, so your files never leave your device.
Is there a limit on file size or number of PDFs?: No fixed limit. You can combine as many PDFs as you like, though very large files may take longer since your device does all the processing.

1
Nothing is uploaded
The file never leaves your device. There is no server to send it to, so there is nothing to leak, log, or subpoena.
2
No signup, no limits
No account, no email, no daily cap, no watermark, and no paid tier waiting behind the third file.
3
Works offline
Load the page once and it keeps working with the network off, because all the work was always happening locally.