Safe Encryption

Paste text, and get back an encrypted block you can keep anywhere. The encryption is ordinary 7-Zip AES-256, so the result is a real .7z archive that 7-Zip can open years from now — this page is a convenience, not a format you are locked into. Everything happens in this browser tab: nothing is uploaded, and the plain text is never written to your drive.

1 · Key

Key (this is the 7-Zip password — keep it, or the text is gone)

Freshly generated in your browser from crypto.getRandomValues — about 186 bits, far past anything guessable. Type your own if you prefer. Nobody can recover your text without it, including whoever runs this site.

2 · Plain text

Paste the text you want protected

empty

Ready.

3 · Encrypted text

A complete AES-256 .7z archive, written out as base64 so it survives email, notes apps and clipboards

empty

Getting it back without this page

The encrypted block is a real 7-Zip archive in base64. If this site ever disappears, any copy of 7-Zip still opens it — that is the whole point of using a standard format.

Save the encrypted text to a file, say message.b64.

Turn it back into an archive:

base64 -d < message.b64 > message.7z     # macOS: base64 -D
certutil -decode message.b64 message.7z    # Windows

Or skip this step entirely by pressing Download .7z above.

Read it back without ever writing the plain text to disk:
```
7z x -so message.7z -p'your-key-here'
```
-so prints the text to your terminal instead of extracting a file. Drop it and 7-Zip writes message.txt to the current folder, which is exactly what you may be trying to avoid.

Technically: one file (message.txt) stored with Deflate, encrypted with AES-256-CBC, key derived by 7-Zip's own function (SHA-256 iterated 2¹⁹ times over a random 16-byte salt and your key as UTF-16LE). The archive header is encrypted too — 7-Zip's “encrypt file names” mode — so a stray copy on a disk gives away nothing but its size.

What this does and does not protect

Nothing is uploaded. The page makes no network requests at all; its Content-Security-Policy blocks them outright, so this holds even if the code were later changed by mistake.
Nothing is remembered. No cookies, no local storage. Reloading the page loses everything and gives you a new key.
Your key is the whole of the security. Lose it and the text is unrecoverable — there is no reset, by design.
Your device is still your device. This cannot help with a keylogger, a shoulder surfer, a clipboard manager that keeps history, or an operating system that pages memory out to swap.
Browser crash recovery. Some browsers save the contents of text boxes to restore a tab after a crash. This page clears both boxes when you leave it, but pressing Clear everything when you are done is the sure thing.