A few good answers.

No. Your PDF and anything you add are processed in browser memory. Nothing is saved in an account or on our servers. Closing the tab clears the editing session.

Ordinary PDFs, scanned forms, and standard interactive text and checkbox fields. Compatible Adobe forms open as a standard copy, without built-in calculations or validation. Password protected, digitally signed, and XFA-only forms are unsupported. This editor adds content; it does not rewrite existing paragraphs.

A drawn signature is a visible mark on the page. MellowPDF does not create certificate backed digital signatures or certify a document.