When you choose a file
The web editor reads the PDF in your browser. Its page rendering, added annotations and export run on your device. The downloaded copy contains your marks; the original file is not rewritten.
When the extension opens a link
After you click an extension action and grant access to that site, the extension requests the PDF from the source site. That site receives the request. Some authenticated links may not work because the extension does not send your site cookies with its PDF request.
What stays in browser storage
The editor can keep reusable signature images in local browser storage, and it remembers your language choice. Unless you turn it off in Settings, it also keeps the last opened PDF and its undo history on this device so you can continue later; password-protected files are not kept. An extension source URL stays temporarily in extension session storage while a new editor tab opens. Clear browser storage or remove a signature in the editor to remove that local copy.
Limits of visual marks
A white shape only covers content visually. It does not securely remove underlying PDF data. A drawn or imported signature is an image, not a cryptographic signature. Use a verified redaction or signing workflow when those properties matter.
Before sharing a file
Open the downloaded PDF, inspect the marks and check that the intended pages are present. If the document contains confidential content, do not treat visual covering as removal; confirm the file handling rules of the source site and your browser environment.