The SeedSigner+ is an open-source Bitcoin signing device that keeps your private keys off every internet-connected machine you own. It is the upgraded hardware profile of the SeedSigner project and stateless by design: your seed exists only in volatile memory during a signing session and disappears the moment you unplug it. A powered-off SeedSigner+ holds no key material at all, which makes it worthless to a thief who physically steals it.
Per the SeedSigner project’s published seller guidance on seedsigner.com, sellers should never ship devices with preloaded software. Your microSD card arrives blank on purpose. You download the official image, verify the PGP signature, and flash it yourself, which means you never have to trust that a vendor put honest firmware on your device.
Each set is individually packaged, which keeps devices and their SeedQR cards discrete when you are buying multiple units for a multisig quorum.
What wallet software is compatible with SeedSigner+?+
SeedSigner+ works with any wallet that supports QR-based PSBTs (Partially Signed Bitcoin Transactions), including Sparrow Wallet, Specter Desktop, BlueWallet, Nunchuk, Keeper, and Electrum with plugins.
Can I use SeedSigner+ for multisig?+
Yes. SeedSigner+ is built for multisig setups like 2-of-3 or 3-of-5. It can serve as one of your signing devices alongside other hardware wallets or additional SeedSigner units.
Does SeedSigner+ support passphrases (25th word)?+
Yes. You can add a BIP39 passphrase during seed entry for an extra layer of protection. The passphrase is never stored; you enter it each session.
What happens if my SeedSigner+ breaks or gets lost?+
Nothing is stored on the device. As long as you have your seed phrase or SeedQR backup, you can restore your wallet on a new SeedSigner+ or any compatible hardware/software wallet.
Can SeedSigner+ sign transactions for altcoins?+
No. SeedSigner is Bitcoin-only by design. It does not support Ethereum, stablecoins, or other cryptocurrencies.
How do I update the SeedSigner OS?+
Download the latest release from the official SeedSigner GitHub, verify the PGP signature, and flash it to your microSD card. Swap the card in and power on; no internet connection to the device required.
What's the difference between SeedSigner+ and Ledger/Trezor/Coldcard?+
SeedSigner+ is stateless, it never stores your keys. Traditional hardware wallets keep keys on the device permanently. SeedSigner+ also has no wireless hardware and communicates only via QR codes, eliminating USB data attack vectors.
How does the QR code signing process work?+
Your wallet software displays a QR code containing the unsigned transaction. SeedSigner+ scans it, you review and approve, then it displays a signed QR code. Your wallet scans that to broadcast. Keys never touch an internet-connected device.
Can I use my own microSD card instead of the included one?+
Yes. Any microSD card 64MB or larger will work. The included card is provided for convenience; you can swap it for your own if preferred.
Is SeedSigner+ good for beginners?+
SeedSigner+ has a learning curve since you flash your own firmware and manage QR-based signing. It's ideal for users who want maximum security and are comfortable following setup instructions. Beginners can absolutely use it; just expect a bit more hands-on setup than plug-and-play wallets.
How do I install the SeedSigner OS software on my SeedSigner+?+
Download the latest release image from the official SeedSigner GitHub repository, choosing the file that matches the Raspberry Pi Zero v1.3 board inside your device. Verify the PGP signature against the project's published public key, then write the image to the included 1GB microSD card using Balena Etcher or a similar tool. Insert the card into the spring-loaded microSD port, connect USB-C power, and allow about 45 seconds for the SeedSigner logo to appear. The image files are under 42 megabytes, so the download and verification take minutes. The printed instruction page in your box walks through each step.
Can the SeedSigner+ generate a new seed phrase for me?+
Yes, and it can do so in a way no conventional hardware wallet matches. Beyond standard on-device generation, SeedSigner OS lets you generate entropy from a camera photo or from physical dice rolls, with 99 rolls producing a full 24 word seed. Dice entropy means you are not trusting any manufacturer's random number generator, since the randomness comes from physical objects in your own hands. You can also verify the resulting seed independently before ever using it.
Do I need to keep the SeedSigner+ plugged in or charged?+
No. The SeedSigner+ has no battery and holds nothing in storage, so there is nothing to keep charged and nothing to maintain between sessions. You connect USB-C power when you want to sign, load your seed, complete the session, and unplug. A device that sits in a drawer for a year works identically to one used daily. This is a practical advantage over battery powered wallets, where a dead or degraded battery can complicate access at exactly the wrong moment.
Can I power the SeedSigner+ from a wall adapter or power bank?+
Yes. The USB-C port is power-only, so any standard USB power source works, including a phone charger, a power bank, or a computer USB port. Because the port carries no data lines to the board, plugging into a computer creates no data connection and no attack surface. Many users prefer a power bank so the device never physically touches a mains-connected or networked machine during a signing session.
What happens if I lose my SeedSigner+ or it breaks?+
Nothing happens to your bitcoin. Because the device is stateless, your funds were never on it in the first place. Your seed phrase, backed up on paper, steel, or a SeedQR card, is the wallet. Restore it on a replacement SeedSigner+, any SeedSigner build, or any BIP39 compatible wallet and your funds are exactly where you left them. A lost or stolen unit reveals nothing to whoever finds it, since a powered-off SeedSigner+ contains no key material at all.
Can I verify a receive address on the SeedSigner+ before sending funds to it?+
Yes. SeedSigner OS includes an Address Explorer for both single sig and multisig wallets, and you can scan a receive or change address from your wallet software to confirm it belongs to your seed. This protects against malware that swaps addresses on your computer screen. Checking the address on an air-gapped device before large deposits is one of the highest value habits in self custody, and it takes seconds on the SeedSigner+.
Does the SeedSigner+ work with a Bitcoin node?+
Yes, indirectly and by design. The SeedSigner+ never connects to anything, so your coordinator software handles the node connection. Pair Sparrow Wallet or Nunchuk with your own node, such as a Start9 Server One running Bitcoin Core, and you get a fully sovereign stack: your node verifies transactions, your coordinator builds them, and your SeedSigner+ signs them over QR codes. No third party sees your addresses, balances, or transactions at any point.
Can I sign a message with the SeedSigner+ to prove I own an address?+
Yes. SeedSigner OS supports QR based message signing, which lets you cryptographically prove control of an address without moving any funds. This is used for verifying ownership to a counterparty, claiming forked coins, or satisfying proof of reserves requests. The message arrives by QR code, you review it on the 2.8 inch display, and the signed result leaves by QR code, keeping the entire process air gapped.
Is it safe to buy a used or secondhand SeedSigner+?+
Safer than buying almost any other signing device secondhand, though we still recommend against it. Because the device is stateless and you flash the software yourself, a used unit cannot leak a previous owner's keys and cannot hand you a preloaded seed. The residual risk is hardware tampering, which is why the SeedSigner project recommends buying from sellers with community reputations. Every unit from Solo Satoshi comes directly from the project creator's supply chain, fully assembled in the USA.
Does the SeedSigner+ support Taproot addresses?+
Yes. Taproot support has been enabled by default in SeedSigner OS since version 0.8.0, so the SeedSigner+ can sign for bc1p addresses out of the box. Taproot brings efficiency and privacy improvements to Bitcoin transactions, and support on the signing device means you can use modern wallet types in Sparrow or Nunchuk without falling back to older address formats. Keeping your flashed image current ensures you have the latest supported features.
