Tresorit Send
send.tresorit.com
A 5 GB end-to-end encrypted drop that needs no sign-up on either side
wormhole.app
Encrypts the file in your browser, then hands you a self-expiring link.
Wormhole encrypts files client-side and puts the decryption key in the URL fragment, so the service stores something it cannot open and the key never reaches its logs. Transfers run up to 10 GB and the link expires on its own rather than waiting for you to tidy up. The client is open source, which is more than most transfer sites will show you.
Questions
Works the moment the page loads. No account, no email, no trial. Capped at 10 GB and the link expires by itself, so it cannot be used as storage or a permanent host.
Yes. Wormhole sends your input to its own servers to process it. That is fine for public material; for anything containing personal data, use one of the on-device tools instead.
Capped at 10 GB and the link expires by itself, so it cannot be used as storage or a permanent host.
Alternatives
Same category or same task, ordered by how closely they overlap.
send.tresorit.com
A 5 GB end-to-end encrypted drop that needs no sign-up on either side
file.io
Uploads a file and deletes it the moment someone downloads it
pairdrop.net
Finds other browsers on your network and sends files straight to them
fromsmash.com
Sends a file of any size without charging you for the big ones
toffeeshare.com
Streams a file from your browser to theirs with no copy in between
wetransfer.com
Drop a file, type two email addresses, and it sends a download link