Send from this browser
Nothing to install, on your side or theirs. The file goes straight from this tab to whoever opens your link.
or click to choose. Drop as many as you like.
With a password, the link on its own opens nothing and the filename is hidden too. Wrapping it takes about a second on their machine, which is the point: it takes an attacker the same second, once per guess.
How this works, and what it does not do
Your browser holds the file and hands it
to the other browser directly. It is encrypted with AES-256-GCM before it
leaves, and the key travels in the part of the link after the #,
which browsers never send to a server. So nothing in the middle can read it,
including us.
Both of you have to be online at the same time, because there is no copy stored anywhere to collect later. If you need to send something and walk away, or you want to send folders and very large files without keeping a tab open, the Windows app does that.