How to Send a Message Only One Person Can Read
Sometimes you want to send something that should not sit in a chat history forever - a password for a new account, a surprise, an answer nobody else should see yet. The Encrypted Message tool encrypts text and gives you a link that expires on its own.
What the tool actually does
Your message is encrypted in your browser, before anything is sent. What leaves your device is already unreadable, and the link you share is what lets the recipient's browser turn it back into text.
The link also expires. That is the part that matters more than people expect, because the usual problem with a shared secret is not interception - it is that the message stays readable in someone's inbox or chat history for years, long after anyone remembers it is there.
So the two properties together are: unreadable in transit, and gone afterwards.
The habit that undoes it
Do not send the link and the key down the same channel.
If you paste both into the same chat, anyone who can read that chat has everything. The protection comes from separating them - the link by email and the key by text message, or the link in writing and the key spoken aloud.
This is the single most common way people defeat this kind of tool, and it is worth more than any technical detail. One channel means no protection at all.
Where it genuinely helps
Sending a password or an API key to a colleague, where the alternative is leaving it in a chat log permanently.
A surprise you want read at a particular moment rather than the moment it arrives. For something scheduled rather than merely private, the SurpriseQR tool is built around a time lock.
An answer, a result or a spoiler that a group should get at the same time.
Anything you would rather not leave sitting in a message history - which, once you start thinking about it, is a surprising amount.
What it is not
Not a secure messaging platform, and not protection against a determined, well-resourced adversary who already has access to your devices or accounts.
It is a sensible way to avoid leaving plain text lying around, which is a real and ordinary risk. If what you are protecting is genuinely high-stakes, you want end-to-end encrypted messaging with verified contacts, not a link.
And a reversible transformation is not encryption at all - if a tool simply scrambles text in a way anyone can unscramble without a key, that is obfuscation. The distinction is covered by the Base64 encoder, which is the thing people most often mistake for encryption.
Common questions
What happens when the link expires?
It stops working. The recipient needs to open it before then, so tell them roughly when it was sent.
Can I read it again myself?
Only while the link is live. Keep your own copy of anything you will need later.
Is the message stored anywhere readable?
It is stored encrypted. Without the key it is not readable by anyone holding it.
What if I lose the key?
The message is unrecoverable, which is the point. Send a new one.
Can I use it for a long document?
It is built for short text - a password, a note, an answer. A document wants a file-sharing service with permissions.
Got something that should not sit in a chat forever?