Nowser is a free, open-source key management and signing application for the Nostr network. It is aimed at users who want to keep their private keys under control while still signing into Nostr web apps and clients. The program is cross-platform and is distributed for Windows, macOS, Linux, Android and iOS, with a web and browser-extension component listed among its supported platforms.
The main idea behind Nowser is separation: your private key stays in one protected place, and the apps you use only receive signed results. Instead of pasting a secret key into every website or client, you approve each signing request in the app that holds the key. The project is developed with Dart and Flutter, and the current release is 1.4.1. Its last code update was made on December 12, 2025, so it is actively maintained at the time of writing.
What Is Nowser and Why Key Management Matters
Nostr is an open protocol for social networking in which identity is a cryptographic key pair rather than an account on a central server. Whoever controls the private key controls the identity, and there is no password reset to recover it. That makes key handling the most important security question for any Nostr user.
Nowser exists to answer that question. It holds the keys in one place and handles the signing, so that other applications never need to see the secret itself. For someone who uses several Nostr clients across a phone and a laptop, this keeps the key from being copied into every app.
Who Nowser Is For
Nowser suits people who already use Nostr regularly and want a clear boundary between their identity and the software they run. Typical users include:
- People who sign into several Nostr web apps and want one controlled place to approve requests.
- Desktop users who prefer their keys to stay on a phone, using a remote signer for everyday work.
- Android and iOS users who want the operating system's secure storage to protect their keys.
- Users who plan to pair the software with a hardware signer for the highest level of key isolation.
If you are new to Nostr, it is worth learning the basics of public and private keys first, because the tool assumes you understand that losing a private key means losing access to the identity.
How Remote Signing Works in Practice
In a remote signing setup there are two sides. The signer, which is Nowser on your phone, holds the key. The client, such as a Nostr app on your desktop, builds an event and asks the signer to sign it. The signer shows the request, you approve or reject it, and only the resulting signature travels back.
This design means the desktop client can post notes and messages on your behalf without ever possessing the key. If you stop using the desktop, you can revoke access from the signer without changing your identity, because the identity was never stored on the desktop in the first place.
Understanding Nostr Keys and Signing Terms
A few terms come up constantly in Nostr key management, and knowing them helps you use Nowser correctly. The private key, often written in its nsec form, is the secret that signs your events. The public key, written as npub, is the identity others see and can use to find you. Signing is the act of producing a proof, using the private key, that an event really came from you.
A bunker or remote signer is a service that signs on your behalf while keeping the private key elsewhere. A browser extension is the older model, where a plugin in the browser holds the key. Nowser brings that same role to mobile devices, which is why NIP-07 support matters.
Key features
NIP-07 signing for web apps
NIP-46 remote signing
NIP-55 Android key storage
Nesigner hardware signing
Supported coins
Nowser is built around the Nostr network, which is the only network listed for its documentation. It is a signing tool for Nostr identities rather than a wallet for cryptocurrencies, so it does not manage balances or transfers on other blockchains.
How to install Nowser on Windows
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Step 1: Open the official release page
Go to the project's GitHub Releases page at https://github.com/haorendashu/nowser/releases, or start from the project's official site. Download the only from the official website or the Releases page to avoid counterfeit builds.
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Step 2: Choose the Windows build
On the release page, find the latest version, 1.4.1 at the time of writing, and pick the Windows build or installer. The release also contains builds for other platforms, so make sure you select the Windows file.
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Step 3: Verify the file
Before running anything, check the SHA-256 checksum or signature if the release page provides one. Compare the value you calculate locally with the published one. A mismatch means the file was altered and should be discarded.
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Step 4: Install and launch
Run the installer and follow the prompts, or extract the portable build to a folder you control. Start Nowser, create or import your keys, and set up the signing method you need, such as NIP-07 or NIP-46.
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Step 5: Connect a client
Configure the Nostr app or web service you want to use so that it requests signatures from Nowser. Test with a harmless action first to confirm the approval prompt appears as expected.
System requirements
- Windows build or installer available on the official release page
- Current version 1.4.1 from the project's GitHub Releases
How to use Nowser
Nowser is designed to run in the background while other Nostr applications ask it for signatures. Your workflow is mainly about setting up the key once and then approving requests as they come in. A short routine keeps the setup predictable and safe.
- Create or import the Nostr key you want to use, and store a backup of the private key somewhere offline.
- Choose the signing method that matches your setup, either NIP-07 for web apps or NIP-46 for a remote desktop client.
- Pair your desktop or browser client with Nowser using the connection string or QR code the app provides.
- Send a test signature from the client and confirm that the request appears in Nowser before it is approved.
- Review each signing request carefully, checking the event kind and content, and only approve actions you intended.
- Revoke or disconnect a client you no longer use, so that its access ends cleanly.
- Keep the app updated to the latest release and re-verify the checksum each time you upgrade.
Pros & cons
- Keeps private keys off desktop and third-party software when used with a remote signer
- Supports NIP-07, NIP-46 and NIP-55, covering web, desktop and Android scenarios
- Uses native Android key storage through NIP-55
- Free and open source, so the code can be inspected
- Actively updated, with the latest code change in December 2025
- Requires a clear understanding of Nostr keys, which may be unfamiliar to newcomers
- Remote signing depends on the signer device being online and reachable
- Nesigner hardware signing is a separate purchase and setup step
- Separate builds are needed for each platform, so attention is needed when downloading
- Documentation is focused on Nostr concepts, so beginners may need extra reading
Is Nowser safe?
Nowser handles private keys, so treat installation with care. Download it only from the official website or the GitHub Releases page, and verify the SHA-256 checksum or signature before running the file. Never enter your seed phrase or private key on a third-party website, including any page that claims to offer a "Nowser" download or support. Keep a secure offline backup of your keys, and do not share your nsec with anyone. Because the project is open source, you can review its code on GitHub, which is a useful transparency measure for software of this kind.
- Official source only. Download from github.com/haorendashu/nowser. 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
Nowser differs from general Nostr clients in its purpose. Clients like Amethyst, Gossip or Coop are where you read, write and message. Nowser is not meant to replace them; it is the component that guards the key while those clients do their work. In that sense it sits alongside a client rather than competing with it.
Compared with command-line tools such as NAK or Nostr Commander RS, Nowser offers a graphical interface and mobile support, which suits everyday users better. The trade-off is that you rely on a separate app to do the signing. If you use a desktop client that supports remote signing, Nowser is the piece that makes the setup private.
Specifications
- Price
- Free
- Type
- Open source
- License
- —
- Latest version
- 1.4.1
- Last update
- 12 Dec 2025
- Windows support
- Yes (Windows build or installer)
- Source code
- github.com/haorendashu/nowser
Frequently asked questions
Yes, Nowser is free. It is an open-source project, and the source code is published on GitHub. There is no price listed for the program, so you can download the current release from the official Releases page without paying.
It can be, provided you download it only from the official GitHub Releases page and verify the SHA-256 checksum or signature before running it. Avoid third-party download sites, and never enter your private key into a page you do not trust.
NIP-07 is a standard that lets web applications request signatures from a signer instead of holding your key. Nowser can act as that signer, so you can sign into Nostr web apps while your private key stays inside the app.
With NIP-46, your private key stays on your phone in Nowser, and your desktop client sends signing requests to it. You approve each request on the phone, and only the signature is returned, so the desktop never holds the secret.
Nowser is available as a Windows build, so you can run it on the desktop. Remote signing, however, is designed around a phone acting as the key holder, so you should consider which device you want to store your private key on before setting it up.
It helps. Nowser deals with Nostr keys, signing requests and identities, so understanding the difference between public and private keys makes the approval prompts much clearer and reduces the chance of approving something by mistake.
Nesigner is a hardware signer option that stores keys and processes sign requests on a dedicated device. You do not need it to use Nowser, but it is a good choice if you want the private key completely separated from any software on your computer or phone.
Verdict
Nowser is a sensible choice for Nostr users who want their private keys kept away from everyday apps. Its support for NIP-07, NIP-46 and NIP-55 covers web, desktop and Android scenarios, and it is free and open source. It suits people who already understand Nostr identities and want stronger control over signing. Beginners should learn the basics of keys first, and everyone should download the latest release from the official source and verify it before use.