Can you use an encrypted messenger without installing an app?

Option 1: the ephemeral room tools

Tools like Chitchatter and the LOCK.PUB class of encrypted-room sites deserve real credit. They are genuinely end-to-end encrypted, need no account of any kind, and the whole experience is: open a URL, share it with the other person, start talking. For a one-off sensitive conversation — a journalist taking a first contact, two people who need ten private minutes — they're excellent, and they're the fastest path to encryption that exists.

The honest limits are structural, not flaws: the room is the product. There's no persistent identity, no contact list, and no message history — close the tab and the conversation is gone. In most of these tools both parties need to be present at the same time, because there's nowhere for a message to wait. That makes them ephemeral rooms, not messengers. If you'll ever want to message the same person twice, you'll feel the gap immediately.

Option 2: the "web version" that needs an app anyway

This is where most people get caught. WhatsApp Web looks like a browser messenger, but it only unlocks after you link it to a phone that's already running the WhatsApp app (by QR scan or a one-time code) — no installed app, no WhatsApp Web. Signal Desktop is one step further from no-install: it's itself an installed application, and it too must be linked to a phone already running Signal. (Signal has no browser version at all, and has said it won't build one — full explainer: does Signal have a web version?) Threema's web and desktop clients follow the same pattern, linking to its paid phone app.

None of this is a criticism of those products — the companion model is a deliberate security choice, and all three are solid encrypted messengers. But call it what it is: these are companions to an installed app, not no-install messengers. If you can't install the phone app, the "web version" is a locked door.

Option 3: the web client that needs an account

Wire is the closest thing to an exception among the established players: it has a real, standalone browser client that doesn't piggyback on a phone. It's a polished, well-regarded product. The catch is registration — Wire needs an account, so while it clears the no-install bar, it doesn't clear the no-identifier bar. If your goal is simply "encrypted messaging in a browser" and an account doesn't bother you, Wire is a legitimate answer. If the identifier is the problem, it isn't.

Option 4: the persistent no-install lane

This is the lane Sendant occupies, and as far as we can tell it occupies it alone: it is the only identifier-free messenger with a persistent no-install browser client. Open app.sendant.io and you get a real messenger — persistent identity, contact list, message history, delivery to people who are offline via an offline mailbox — with no phone number, no email, and no account. Your identity is a cryptographic key generated on your device. The browser client runs the same WASM-compiled X3DH + Double Ratchet crypto path as Sendant's native app, and it's built for throttled, restricted, or intermittent networks. Because it's a browser app, it works on iPhone right now, in Safari — no App Store required. Full comparison: Sendant vs Signal.

The honest browser-trust note: a browser client is re-delivered by the server on every visit, which makes it a harder trust model than an installed app that's fetched once and verified by an app store. Treat the browser as the low-friction tier and an installed app as the higher-assurance tier. The browser is also the lighter tier in features: it covers text, photos, files and voice calls while the tab is open, and Sendant's app adds push notifications, calls that ring when it is closed, video calls, voice notes, groups and encrypted backup. Sendant has not yet been independently audited — an audit is planned — and we'd rather say that plainly than let you assume otherwise.