Cookies and local storage
This page explains what the site stores in your browser. The short answer: nothing that is used to track you.
No advertising tracker
The site installs no advertising cookie, no social network pixel and no analytics tool. No consent is therefore requested when a page opens: a banner with no technology to block would be pointless.
Local storage
The files you select, the thumbnails and the results stay in memory inside the tab. They are not written to the browser's local or session storage, and they disappear when the tab closes.
Your browser may, on its own, keep technical data (a cache of pages and scripts) to speed up loading. That cache is cleared with your browser's tools and contains none of your documents.
If that changes
If an optional technology were added, it would be blocked by default, a clear choice would be offered (accept or refuse), and withdrawing consent would stay as simple as giving it.
To find out who publishes the site and where files are processed, see the About page.