Bitwarden Send
bitwarden.com
Shares a password through a link that stops working after one view
Free tier
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Move a large file to someone else without an account.
bitwarden.com
Shares a password through a link that stops working after one view
file.io
Uploads a file and deletes it the moment someone downloads it
onetimesecret.com
Puts a secret behind a link that destroys itself once it is opened
pairdrop.net
Finds other browsers on your network and sends files straight to them
send-anywhere.com
Pairs two devices with a six-digit key instead of sending a link
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
send.tresorit.com
A 5 GB end-to-end encrypted drop that needs no sign-up on either side
wetransfer.com
Drop a file, type two email addresses, and it sends a download link
wormhole.app
Encrypts the file in your browser, then hands you a self-expiring link
Privacy
These process everything inside the browser. Load the page, disconnect from the network, and they still work.
pairdrop.net
Finds other browsers on your network and sends files straight to them
toffeeshare.com
Streams a file from your browser to theirs with no copy in between
By task
Archive
Kept on record so an old bookmark still leads to an answer. Each one names the site that does the job now.
mybloop.com
Offered unlimited free file storage, which went about as well as expected
Questions
There is no single answer, which is why this page lists 10 of them with their limits stated. If you want to avoid signing up entirely, 6 of these work with no account at all.
2 of the 10 sites here process your file inside the browser and never upload it — they are marked "On device". The rest send your input to their server, which is fine for public material and worth thinking twice about for anything personal.
Some already have. 1 entry in this category has been retired and moved to the Archive with a working successor, so an old bookmark still leads somewhere useful.