Yes, adding page numbers to PDF is completely free on PDFA2Z.

Can I start from a custom number?

Yes, you can set any starting number (e.g., start from page 5).

Add Page Numbers to PDF Free

Professionally number your PDF pages. Choose exactly where numbers appear — top or bottom, left, center, or right — and customize font and starting number.

Upload your PDF.
Choose number position (header or footer) and alignment.
Set starting page number and font size.
Download your numbered PDF.

Is it free?: Yes, adding page numbers to PDF is completely free on PDFA2Z.
Can I start from a custom number?: Yes, you can set any starting number (e.g., start from page 5).