Share a secret that can be read exactly once.
The note is encrypted in your browser with AES-256-GCM before it leaves this page. The decryption key lives in the link fragment (after #) and is never sent to the server. The note is destroyed on first read, or when it expires.
Your one-time link
Anyone with this link can read the note once. The key after # never reaches the server, so this link is the only copy — if it is lost, the note is unrecoverable.
Send a file
Share an image or document the same way: it is encrypted in your browser, can be downloaded exactly once, and is destroyed on first download or at expiry. The filename and type are encrypted too — the server never sees them.
Your one-time file link
Anyone with this link can download the file once. The key after # never reaches the server, so this link is the only copy — if it is lost, the file is unrecoverable.