[ortekk]

See also Firefox Send - https://send.firefox.com/

Files are encrypted and then uploaded to Mozilla servers. Links automatically expire after some time.

[irl_]

This is not metadata analysis resistant, so Mozilla could still technically see who is sending files to who (unless you use Firefox Send in Tor Browser - not sure how well that works).

That's not to say this service isn't useful, but it's not a drop-in alternative to OnionShare.