Nymchat is a free, open-source chat client built on the Nostr protocol. It is made for people who want quick, temporary conversations without building a lasting message history, including privacy-minded users, local community groups and Nostr enthusiasts. Its lightweight, IRC-like feel makes it easy to join a room and talk, even if you are new to decentralized networks.
Nymchat is bridged with Bitchat, a separate messaging app, so its pseudonymous, temporary messages can reach that community too. Windows appears among the platforms named in the project's documentation, alongside Android, iOS and web. Because that Windows support is less clearly confirmed than the others, read the release notes before you rely on the desktop version.
What Is Nymchat and How Does It Work?
Nymchat is a chat client, meaning it is the app you type into rather than a server that stores your messages for you. It connects to relays in the Nostr network. A relay is a server that receives, stores and forwards signed messages. Because many independent relays exist, no single operator controls the conversation.
When you send a message, your client signs it with your key pair and publishes it to relays. Other clients subscribed to the same channel receive it. Geohash channels group people by location, while the Bitchat bridge lets conversations reach users of that companion app. The ephemeral design means the client does not treat the conversation as a permanent record, so the experience feels closer to a live room than an inbox.
Who Is Nymchat Best Suited For?
Nymchat works best for people who want quick, temporary conversations with fewer personal details attached. A neighborhood group might use a local geohash channel to share road closures or lost-pet alerts without building a permanent group chat. An event organizer could coordinate with attendees in real time, then let the conversation fade once the event ends.
Nostr enthusiasts and developers testing decentralized apps also find it useful, since the code is open and the protocol is public. Journalists gathering quick tips from a region may find it handy as well, though they should review their own security practices first. People who need guaranteed message history, file archives or business-grade administration should look at other tools.
The best fit is someone comfortable with a simple, text-first tool that puts privacy ahead of convenience.
Ephemeral Chat Trade-Offs: Privacy Expectations and Limits
Ephemeral messaging reduces how much chat history persists on your own device, but it does not make you invisible. Pseudonymous means you can use a name that is not tied to your legal identity. It does not hide the fact that your device connects to relays, and relay operators can see the events they handle.
Other participants can copy what you write, take screenshots or repeat it elsewhere. Treat each message as potentially public, even inside a temporary room. A general question about a neighborhood is fine to post, while home addresses, financial details or private keys should never appear in a chat.
Understanding these limits keeps your expectations realistic and helps you use the tool well.
Key features
Ephemeral messaging
Geohash location channels
Bluetooth mesh support
Nostr-based identity
Supported coins
The project's documentation references Bitcoin (BTC), Flux, Nano and the Lightning Network, alongside Nostr itself. These mentions describe the wider ecosystem Nymchat connects with, not wallet features inside the chat client. Ledger hardware wallets and the SHA-256 mining algorithm are also mentioned in the documentation, but Nymchat is a messaging tool, not a wallet or a mining program.
How to install Nymchat on Windows
- 1
Download the latest release
Open the project's GitHub Releases page at github.com/Spl0itable/NYM and download the current build, listed as v3.75.545. Download only from the official website or that repository, and avoid mirror sites or links shared in chats.
- 2
Verify the file
Compare the SHA-256 checksum of the downloaded file with the value published alongside the release. If a signature is provided, check that as well. Stop and do not install if the values do not match.
-
Install and launch
Run the installer, follow the prompts and open Nymchat. If Windows or your antivirus warns about an unfamiliar program, confirm the checksum first rather than turning protection off.
How to use Nymchat
Nymchat is simple to start, but a few habits make conversations more useful.
- Open the client and choose a display name. Pick something that does not reveal your real identity.
- Select a geohash channel for your area, or join a general room.
- Read the room for a few minutes before posting, so you understand its tone and topics.
- Send short, specific messages. Because conversations are temporary, repeat key details when someone may have missed them.
- Test the Bitchat bridge with a friend if you use both apps, so you know how messages appear on each side.
- When you finish, close the client. Do not assume a message will be retrievable later, and copy anything important somewhere safe before it disappears.
Pros & cons
- Free and open source under the AGPL-3.0 license
- Ephemeral messages leave little long-term history on your device
- Pseudonymous chat without an email-based account
- Lightweight, IRC-like experience that is easy to join
- Bridged with Bitchat for a wider audience
- Location channels built on geohash areas
- Windows support is named in the documentation but less clearly confirmed than other platforms
- Temporary messages mean there is no searchable history
- Pseudonymous chat does not guarantee full anonymity
- Bluetooth mesh behavior depends on platform and build
- Getting the most from it requires understanding relays and keys
Is Nymchat safe?
Nymchat is licensed under AGPL-3.0, and its source code is public on GitHub, which lets anyone review how it works. Download Nymchat for Windows only from the official website or the project's GitHub Releases page. Before running the installer, compare the file's SHA-256 checksum with the value the project publishes, or verify its signature if one is provided.
Never enter a seed phrase, wallet key or Nostr private key on third-party websites, including sites that claim to verify, upgrade or recover your account. Keep your operating system and security software up to date. Check the latest version on the official website before installing, since older builds may lack current fixes.
- Official source only. Download from github.com/Spl0itable/NYM. 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
Nymchat differs from the other Nostr tools in this catalog mainly in purpose. Vega and Nostrid are general-purpose Nostr clients for browsing and posting, and Notedeck focuses on a Rust-based desktop browser for the network. Keychat is closer in spirit because it is also a chat app built on Nostr, with bitcoin and ecash support.
Nymchat leans toward temporary, pseudonymous rooms with geohash channels and a Bitchat bridge. If you want a messenger that keeps conversations and supports payments, Keychat is the better fit. If you want ephemeral, IRC-style conversations, Nymchat is the more natural choice.
Specifications
- Price
- Free
- Type
- Open source
- License
- AGPL-3.0
- Latest version
- v3.75.545
- Last update
- 1 Nov 2026
- Windows support
- Unverified (Windows mentioned in docs)
- Source code
- github.com/Spl0itable/NYM
Frequently asked questions
Yes, Nymchat is free and released as open-source software under the AGPL-3.0 license. You can read its source code on GitHub, review how it works and even build it yourself. No subscription or purchase is needed to start chatting. The AGPL license also requires that modified versions you distribute remain open source under the same terms.
Windows is named among the platforms in the project's documentation, alongside Android, iOS and web. Treat the desktop version as less certain than the mobile or web options. Read the release notes on GitHub before installing, and try a short test conversation first to see how the Windows build behaves on your computer.
Nymchat is open-source software, so its code is public for anyone to review. Safety depends mostly on where you download the program and how you handle your Nostr keys. Get the installer only from the official website or GitHub Releases, verify its SHA-256 checksum and never paste your private key into a site you do not trust.
Ephemeral chat means messages are meant to be temporary rather than stored permanently. Conversations are useful for quick coordination, but they do not form a searchable archive. Assume that anything you type can be copied by another participant, even if the app itself does not keep a long history of what was said.
Nymchat uses pseudonymous messaging, so you can chat without using your real name. That is not the same as full anonymity. Relay operators, network metadata and screenshots taken by other users can still reveal information, so avoid sharing details that could identify you or your location precisely.
Nymchat is a chat client, not a wallet, so it does not hold your funds. Its documentation mentions Bitcoin, the Lightning Network and other networks as part of the wider ecosystem. Use a dedicated wallet app for payments, and never share a seed phrase or wallet key inside a chat conversation.
Verdict
Nymchat is a focused, open-source tool for temporary, pseudonymous chat on the Nostr network. It is free under AGPL-3.0, and its geohash channels and Bitchat bridge set it apart from general-purpose Nostr clients. It suits privacy-minded people, local community groups and Nostr enthusiasts who want IRC-style conversations. It is less suitable for anyone who needs permanent message history or fully confirmed Windows support. Start with a test conversation before relying on it for anything important.