Classified Doc

Your document is encrypted before it ever becomes a file. AES-GCM with a 256-bit key, derived from your password with PBKDF2-SHA256 at 600,000 iterations — the OWASP recommendation. The file's header records those settings so the file stays readable if they ever change, and the header is authenticated too: altering it makes the file refuse to open rather than quietly weakening it.

Nothing is saved in your browser. No local storage, no cookies, no database, not even your preferences. That is a real trade and you should know which way it cuts: close this tab with unsaved changes and that writing is gone, because there is no recovery copy anywhere. The page warns you before it happens.

Nothing is sent anywhere. This page declares a Content Security Policy of connect-src 'none', which means the browser itself refuses to let it open a network connection. You can check that in your browser's developer tools rather than taking my word for it. It also loads no third-party JavaScript at all.

What is left on the server: one line in a web log saying this page was requested — the same line any page produces, with nothing in it about you or your document. The site's fonts come from Fontshare and Google Fonts, as they do on every page here; they see that a browser loaded a page, never a word of what you write.

What this cannot do. It cannot recover a forgotten password — there is no hint and no back door, so a lost password means a lost document. Consider storing the password in a password manager. And while your document is open, its text is in the page's memory; every reference is dropped when you lock or close it, but no browser tool can promise the bytes are scrubbed from RAM the instant you do. Anything claiming otherwise is overselling.