Iris Chat is a free, open-source encrypted messenger for people who want private conversations without giving up an email address or phone number. It runs as a web app that you can install on a Windows PC, and it also works on Android and iOS. If you want a messenger that keeps control of your identity in your own hands, this is a serious option to try.
Messages are protected with end-to-end encryption built on the double-ratchet protocol, and the app is built on Nostr, an open network where no single company holds your account. Your data is stored on your device by default. Iris Chat suits privacy-minded users, small friend groups and developers who prefer open protocols over closed platforms. It is also a practical choice for anyone who wants to test decentralized messaging before committing to it.
What Is Iris Chat and How Does It Work?
Iris Chat is a messaging client rather than a server you have to run yourself. When you send a message, it is encrypted on your device and passed through the Nostr network to the recipient, who decrypts it with keys only they hold. Relays carry the encrypted payloads, but they cannot read the contents of a direct message.
The double-ratchet protocol is the core of the design. Keys advance with every exchange, so the conversation keeps producing new secrets rather than relying on one key for everything. That matters because a messenger's security should not depend on a single secret staying hidden forever.
Because there is no email or phone registration, your identity is a cryptographic key pair instead of a number tied to a SIM card. You control that identity, which also means that losing access to your keys means losing access to the account. Treat your keys as the most important thing you keep in the app.
Who Is Iris Chat For?
Iris Chat fits people who care about where their messages live and who holds the keys. Privacy-focused users who do not want to hand over a phone number are an obvious group. Developers and Nostr enthusiasts who want a working client on an open protocol they can inspect will also find it useful.
Small communities and friend groups can use it to coordinate without a central company controlling the channel. A freelancer or activist who needs a contact channel that is not tied to a personal phone number may find the registration-free model appealing. The app works well when everyone involved is willing to try it.
It is less suited to someone who needs to reach people on a mainstream messenger only. Your contacts need to be on the same open protocol to reach you, so the first step is often inviting a handful of people you already trust. Starting with a small test group is a practical way to see whether the workflow fits your habits.
Can a Decentralized Messenger Replace Your Current App?
Replacing a mainstream messenger is a bigger step than installing a new program. Most people keep several apps running, and a decentralized client works best as a second channel at first. Use it for conversations where privacy and independence matter most, then decide whether to move more contacts over over time.
Decentralization has trade-offs. Without a central company, there is no support desk to reset a forgotten key. Account recovery depends on the keys you keep safe, not on a customer service team. Read the documentation carefully before relying on the app for anything critical.
The design also shifts responsibility. Instead of trusting a platform to protect your account, you trust your own key management and an open protocol. That shift suits some people and frustrates others, so test it with a small group before deciding.
Key features
End-to-End Encryption with Double Ratchet
QR Code Invites
Push Notifications
Installable Web App
Local-First Storage
NIP-07 Key Management
Voice and Video Calls
Linked-Device Sync
Supported coins
The documentation names Nostr as the network the messenger runs on. Nostr is a communication protocol rather than a cryptocurrency, so Iris Chat does not involve coin transfers in the way a wallet does. Hardware wallet support is listed for Ledger, which matters mainly for users who manage keys alongside other Web3 tools.
How to install Iris Chat on Windows
- 1
Get the Windows Version
Go to the official website or the project's GitHub Releases page and download the Windows build or installer. The current release is v2.6.45. Pick the latest release listed on the page rather than a copy from a forum or chat group.
- 2
Verify the Download
Calculate the SHA-256 checksum of the file and compare it with the value published alongside the release. If a signature is provided, check it as well. Do not run a file whose checksum does not match the published value.
- 3
Run the Installer
Open the downloaded file and follow the installation prompts. Installation is free and does not ask for an email address or phone number. Keep your antivirus protection active during setup.
-
Start Chatting
Open Iris Chat and add a contact by scanning a QR code invite or by sharing your own. Allow notifications if you want alerts when the window is closed. Grant microphone and camera access only when you plan to make a call.
System requirements
- A Windows PC capable of running a current web browser or the Windows build
- Microphone and camera access for voice and video calls
- A secure browser context, which is required before the app can use the microphone or camera
How to use Iris Chat
Once installed, the basic workflow takes only a few minutes. Most of your time will go into setting up contacts and checking privacy options.
- Open Iris Chat and create or restore your identity so the app has keys to work with.
- Back up your key material somewhere safe and offline before you add contacts, since your keys are your account.
- Share your QR code invite with a friend, or scan theirs with your camera. Doing this in person is the simplest way to confirm you have the right person.
- Send a short test message and confirm the other person sees it before moving on to longer conversations.
- Turn on push notifications through your browser or installed app settings if you want alerts while the window is closed.
- Link a second device when you need the same conversations in another place, then confirm that sync works in both directions.
- Start a voice or video call only after granting microphone and camera access, and make sure you are on a secure connection.
Pros & cons
- Free to use and open source, with the code published on GitHub
- No email address or phone number needed to register
- End-to-end encryption built on the double-ratchet protocol
- QR code invites make the first connection quick
- Installable as a web app across Windows, Android and iOS
- Local-first storage keeps conversation history on your device
- Supports NIP-07 extensions for key management
- Voice and video calls use adaptive bitrate for changing connections
- Your contacts must use the same open protocol to reach you
- Calls need microphone and camera permission and a secure browser context
- Losing your keys means losing access, with no support desk to recover them
- Much of the app is web-based, so its behavior can depend on your browser
Is Iris Chat safe?
Iris Chat handles cryptographic keys, so treat installation with the same care you would give a crypto wallet. Download only from the official website or the GitHub Releases page, and avoid mirror sites or files shared in chats. Verify the SHA-256 checksum or signature before running any file, and keep antivirus protection active. Never enter a seed phrase, private key or recovery phrase on third-party websites, including those that claim to offer support or upgrades. Your keys define your account, so store backups offline. The project's code is recently updated, but it is still worth checking the latest version on the official website before installing.
- Official source only. Download from github.com/irislib/iris-chat. Ignore ads and lookalike domains.
- Check the SHA-256. Compare the installer hash with the value the developer publishes before running it.
- Never share your seed phrase. No developer, support agent or website — including CryptApps — will ever ask for it.
Alternatives
Iris Chat differs from the similar programs in this catalog mainly in its foundation. It runs on Nostr and uses the double-ratchet protocol for direct messages, and it is delivered as a web app that installs on Windows, Android and iOS. Loquaz is a desktop application written in Rust for direct encrypted chat, so it is a native program rather than a browser-based client. Session Desktop is a privacy messenger built on the Oxen network, which is a different underlying network from Nostr. Quorum Desktop is a group messenger powered by Quilibrium and the libp2p stack, which makes it a better fit for group-first use. Choose Iris Chat when you want a lightweight, browser-based client on an open protocol.
Specifications
- Price
- Free
- Type
- Open source
- License
- —
- Latest version
- v2.6.45
- Last update
- 29 Oct 2026
- Windows support
- Yes (Windows build or installer)
- Source code
- github.com/irislib/iris-chat
Frequently asked questions
Yes. Iris Chat is listed as free, and its source code is published on GitHub, so you can read how it works. You do not need to pay to install it on Windows or to start a conversation. The app also does not ask for an email address or phone number during sign-up, which keeps the setup short and simple.
It uses end-to-end encryption built on the double-ratchet protocol, and its code is open for review. Safety also depends on how you install the app and how you protect your keys, as covered in the safety section above. A careful setup makes Iris Chat a reasonable choice for private conversations, though no messenger removes every risk.
No. Registration does not require an email address or phone number, because your identity is based on a cryptographic key pair. That means you control the account directly. The trade-off is that losing your keys can mean losing access, so keep backups stored safely offline. This setup suits people who want to limit the personal data they share with messaging services.
The double-ratchet protocol is an encryption method that keeps updating keys as messages are exchanged. Each message can use a new key, so a single compromised key does not expose the entire conversation. It belongs to the same family of designs used in several well-known private messengers, and it is the core of how Iris Chat protects direct messages.
Yes. Calls use WebRTC with Opus audio and adaptive bitrate, so quality adjusts when your connection changes. You must grant microphone and camera access in the browser, and the app needs a secure browser context for that access. If a call fails to connect, check the permissions first.
Nostr is an open protocol for sending signed messages through a network of relays rather than through one central server. Iris Chat uses Nostr as its network layer, so your identity and messages do not depend on a single company's infrastructure. The documentation lists Nostr as the network the messenger runs on.
Iris Chat's documented focus is secure direct messaging, QR invites and linked devices. If your main need is large group messaging, compare it with Quorum Desktop, which is described as a group messenger. Matching the app to your daily habits is the best way to decide.
Verdict
Iris Chat is a strong pick for people who want an open, encrypted messenger that does not require a phone number or email address. It is free, open source and built on Nostr with the double-ratchet protocol. Choose it if you value control over your identity and are comfortable managing your own keys. It is less ideal if you need to reach mainstream contacts instantly or want a fully native desktop program. Try it with a small group of trusted contacts first, and expect a short learning curve.