Secure messenger FAQ

Does Sendant need a phone number?

No. Sendant creates a cryptographic identity on your device, so you do not need to provide a phone number, email address, or account.

That reduces the personal data exposed at signup and makes Sendant easier to use when you want to talk without tying the conversation to a SIM card or address book identity. Curious why other messengers insist on one? See why Signal needs your phone number. For services outside Sendant that still ask for email, Emcognito lets you use a private alias instead of your primary inbox.

Do I need an email address or an account?

No. There is no signup form, no password, and no inbox to verify.

Creating an identity generates key material on the device. Nothing checks it against a phone book, an address, or a social profile, so at signup there is nothing to hand over — and afterwards there is no account record mapping a person to a conversation. Connecting with someone is explicit: you exchange an invite link or scan a code.

How do I add a contact without a phone directory?

By invite: you send a link or show a code, and the other person's app answers with its own key.

There is no address book to search, which is the point — a directory that lets you find people also lets anyone else find them, and lets whoever runs it enumerate your contacts. Both sides opt in, one conversation at a time. Group chats extend the same idea: the creator adds members, and each member's app contributes its own keys.

Is Sendant anonymous?

No. Sendant removes the phone number, not your network address: the servers see ciphertext plus the connection itself, including your IP address.

Anonymity and identifier-free identity are different promises, and it is worth being precise about which one you need. If your threat model includes someone watching the network, Sendant does not solve it — it does not claim IP-address hiding and it does not use onion routing. What it removes is the account and the number, which is what most people are actually trying to get away from.

Can I recover my identity if I lose my phone?

Only from an encrypted backup you made yourself. There is no account recovery, because there is no account.

The Android and iPhone apps support encrypted backup; the browser client does not, so a browser-only identity lives in that browser's storage. This is the honest cost of having no server-side account: nobody — including us — holds a key that could restore your history for you. Make the backup before you need it.

Can I use Sendant without installing an app?

Yes. Open app.sendant.io in a modern browser to use Sendant on desktop or a phone with no install. For the best experience, get the app on Google Play or the App Store.

The browser client uses WebAssembly for the same crypto path as the app and covers text, photos, files and voice calls while the tab is open. The app adds push notifications, calls that ring when it is closed, video calls, voice notes, groups, larger files and encrypted backup. Browser E2EE also has real trust tradeoffs, so Sendant avoids calling the browser the highest-assurance tier. For the full landscape of no-install options, see encrypted messaging without installing an app.

Is the browser client a real messenger or a temporary session?

A real one: identity, contacts and history survive closing the tab.

Most encrypted things you can open in a browser are ephemeral chat rooms — a one-off link that dies with the tab. Sendant's browser client is persistent and full-featured, and the tab is a first-class client rather than a temporary session. The limits are concrete: it does one tab at a time, and it cannot receive push notifications while it is closed. Those are stated here rather than discovered later.

What does the app do that the browser client cannot?

Push notifications while closed, calls that ring when the app is closed, video calls, voice notes, groups, larger files and encrypted backup.

The browser is the low-friction tier and the app is the higher-assurance one. An installed app's code changes only when you update it, and its keys get OS-level protection that browser storage does not match — the same tradeoff Signal cites when explaining why it has no web client. If you can install and you want the full feature set, install. If you cannot install, the browser path exists and is not a demo.

Is there an iPhone app, or only the browser?

Both. Sendant for iPhone has been on the App Store since August 2026 (iOS 17+), and the browser client also runs in Safari on an iPhone.

Two ways in, with nothing asked in either. This matters because iPhone users are often told a browser client is a workaround for a missing app — here it is a genuine second path, and the native app is the one with push, ringing calls, video and background delivery. Open the App Store listing or use the browser client.

Which browsers does the browser client support?

Any modern browser that runs WebAssembly — Chrome, Edge, Firefox and Safari, on desktop or phone.

WebAssembly is not an implementation detail here: it is what lets the browser run the same compiled crypto as the native apps instead of a second JavaScript rewrite that slowly drifts. A browser without it cannot run the client at all. If yours is more than a few years old, update it first.

Is Sendant end-to-end encrypted?

Yes. Messages are encrypted on your device before delivery. Sendant servers handle ciphertext, not message text.

Private keys stay on your device. Safety numbers, compared in person or on a call, help people confirm who is on the other end. The full architecture — including what the server can still observe — is on the security page, and the browser's weaker trust model is set out separately in security in the browser.

Which encryption does Sendant use?

X3DH for the initial key agreement and the Double Ratchet for ongoing messages — the same primitives Signal uses.

One Go implementation of both ships everywhere: compiled natively into the Android and iPhone apps, and to WebAssembly in the browser. Using well-understood primitives is a deliberate choice, and so is publishing the protocol and its test vectors so the behaviour can be checked even though the source is private — see how to verify a messenger without its source code.

Can Sendant's servers read my messages?

No. Message content is encrypted on your device before it is sent, so the server stores and forwards ciphertext.

A message waiting in the offline mailbox is an encrypted envelope, not readable text — the mailbox is what makes delivery survive an offline recipient, and it does not require decrypting anything. What the server does see is what any server sees to route a message: that a connection happened, and the network address it came from.

Does Sendant hide my IP address?

No. Sendant does not claim to hide network-level metadata such as your IP address, and it does not use onion routing.

This is the most common thing a privacy messenger is assumed to do and does not. Hiding the network address takes a different architecture with its own costs, and pretending otherwise would be the kind of claim that reads well until someone checks. If an adversary who can watch your traffic is in your threat model, treat Sendant as solving the identity problem, not the network one. The security page says so in the same breath as everything else.

How do I check I am talking to the right person?

Compare safety numbers in person or on a call. Every other signal — a name, an avatar, an invite link — can be forged; that one cannot.

End-to-end encryption protects the channel, not the identity at the other end of it. Safety-number verification closes that gap for the conversation you care most about. It costs a minute, and it is the difference between "encrypted" and "encrypted with the person I think it is".

Has Sendant been independently audited?

Not yet. Sendant is built on X3DH and Double Ratchet primitives, and independent audit work is a launch gate before broad privacy-community promotion.

Until then, Sendant should be evaluated as an early private messenger with transparent limits, not as “battle-tested” or “most secure.” If completed third-party audits are a hard requirement for you today, Signal has years of them and wins that row outright.

Is Sendant open source?

No. The source code is private. The trust story is "verifiable, not open".

What that means concretely: the architecture and protocol are publicly documented, test vectors are published, there is a signed direct Android APK whose certificate fingerprint can be checked against DNS, and behaviour can be observed rather than assumed. What it does not mean is that you can read or compile the code — so please do not treat any claim that you can as accurate. Sendant's own pages avoid the phrase for that reason.

Does Sendant track me?

The apps ship with no analytics or crash-reporting SDK. Privacy-respecting analytics run only on this marketing site, never in the app.

That distinction is deliberate: a messenger that knows who you talk to does not need a third-party SDK in the same process, and shipping one would undo the design. On the site, the beacon is aggregate page-view counting for the pages you are reading now — not in anything you send.

What happens if my contact is offline?

Your message waits as encrypted ciphertext in a store-and-forward mailbox, then delivers when the contact reconnects.

Honest wording matters: Sendant is built for intermittent or restricted networks and offline mailbox delivery. It is not a Bluetooth mesh messenger and should not be described as working with no internet at all.

Step by step: what happens to your message when the network fails.

Does Sendant work with no internet at all?

No. Sendant needs some network path. It is built for throttled, restricted, or intermittent networks — not total blackouts.

If you need messaging with no signal at all, the honest answer is a radio-mesh app such as Briar, which is designed for exactly that and pays for it in range and speed. Sendant's resilience claim is narrower and worth stating precisely: it keeps working when the connection is degraded, and it delivers later rather than failing. Sendant vs Briar covers where each one belongs.

Can I use Sendant on a locked-down work laptop?

Often yes: the browser client needs no install, only a tab. Whether it is allowed is your organisation's decision, not a technical one.

This is the case the browser tier exists for — a machine where you cannot install software, on a network you do not control. Use it where you have authorisation. Sendant does not help you get around an employer's, a school's, or a government's controls, and the pages here will not tell you how.

How is Sendant different from Signal?

Signal is excellent, but it requires a phone number and does not offer a browser web client. Sendant needs no phone number and runs in a browser with nothing to install.

Sendant is not claiming Signal's maturity or audit history. The practical difference is access: identifier-free identity plus a persistent browser client. Full breakdown: Sendant vs Signal, and the story behind Signal's missing web version.

Is Sendant the same as "Sends Messenger"?

No. Sends Messenger is a different, unrelated app, and Sendant has no affiliation with it.

The names are close enough that people land here looking for the other one. Sendant is this project, at sendant.io: the Android app is io.sendant on Google Play and the iPhone app is listed as Sendant on the App Store. If you meant a different app with a similar name, this is not it — and nothing here is a rebrand of it. The /about page carries the full entity record.

What does Sendant cost?

Sendant is free. The one paid option is Pro Relay at $3 a month or $29 a year.

Pro Relay raises relay limits on the web client and Android — files up to 25 MiB sent from Android, 100 uploads a day, media kept 30 days, an offline mailbox that waits 60 days, on up to five devices. It is bought with a passcode rather than an account, so upgrading does not create the account the rest of the app avoids. What Pro changes, and what it does not.

Does Sendant show ads or sell data?

No ads, no token, and no selling of user data. It is funded by the optional Pro Relay subscription.

That is the whole business model, and it shapes the design: there is no advertising identifier to collect, no engagement metric to optimise, and no incentive to keep a profile of who you talk to. The apps ship with no analytics SDK at all, which is a claim you can check by inspecting an installed APK.

How do I move to Sendant from WhatsApp or Signal?

There is no history to import: you create an identity and start new conversations from an invite.

Nothing asks you to abandon the app you already run — keep Signal for the people who are on Signal. Move the conversations that need an identifier-free path or a browser client, and leave the rest. A practical walkthrough is in moving from WhatsApp to Sendant, and the short version is: open app.sendant.io, create an identity, send one invite.