Privacy
What stays on your device, and what the site itself receives.
PDF files
Merge PDF reads the files you select and builds the download in the browser. Those bytes are not sent to PDFZaro in the merge request, because there is no merge request. Previews are drawn on the page from the same local bytes.
What the server does see
Like any website, the server receives the request for the page, the styles, the scripts, and the merge engine. That is ordinary web traffic. It does not include the PDF you selected. Server logs may keep an IP address and the page address for a period controlled by the host.
Contact form
If you send the form, the name, email address, and message are delivered to the site owner. Do not put a document or a password in that message. The form is rate limited.
Analytics
No third-party analytics script is loaded unless one is configured for this installation. The event helper used by Merge PDF can record a count and an error code. It is written so it does not accept a file name, document text, metadata, or a password.
Cookies
The contact page uses a session cookie to protect the form. The merge tool does not need an account cookie.