What is NGRAVE ZERO?

NGRAVE ZERO is a hardware wallet built to stay fully offline. It has a 4-inch touchscreen and a camera, and it exchanges transaction data with a phone only by scanning QR codes. NGRAVE is a Belgian company that says it has been working on self-custody since 2018, and the device is made in Belgium.

How does the NGRAVE cold wallet sign transactions?

The ZERO is an air-gapped device, which means it never connects to a computer or phone by cable or radio. The NGRAVE LIQUID app on your phone builds a transaction and shows it as a QR code. The ZERO scans it, displays the details for you to approve, signs it, and shows a new QR code that the app scans and broadcasts. The general idea is covered in our guide to air-gapped wallets.

As of November 2026, NGRAVE lists support for about 16 coins, including Bitcoin, Ethereum, XRP, Solana, Litecoin, Dogecoin and Stellar, plus ERC-20 tokens and Ethereum NFTs. The ZERO can also sign for MetaMask and Rabby, which lets it be used with other EVM networks and dapps. Firmware 1.8 added an open QR protocol and fingerprint changes. NGRAVE markets the device as EAL7 certified, the top level of the Common Criteria scale, and describes four layers of tamper resistance starting with its metal casing.

What is the NGRAVE Perfect Key?

Instead of showing a word list first, the ZERO generates a 256-bit private key and shows it in hexadecimal form, which NGRAVE calls the Perfect Key. The device can convert it into a 24-word mnemonic and back. You can view it in the settings after entering your PIN.

NGRAVE's academy explains what happens if the company stops operating. A device would keep working, but updates would stop. Anyone with a Perfect Key backup could convert it to a standard BIP39 phrase offline and import it into another wallet. Without that backup, a broken device means lost funds. For the basics of these phrases, read what is a seed phrase.

How does NGRAVE GRAPHENE work?

GRAPHENE is a backup made of two stainless steel plates, each about A5 size and 3 mm thick. The upper plate carries a scrambled grid of hexadecimal characters that is unique to you. You punch your key through it onto the lower plate. Neither plate reveals the key alone, so NGRAVE advises storing them in separate places.

If you lose the upper plate, NGRAVE can make a replacement using a recovery code, because it knows nothing about the lower plate. GRAPHENE holds only hexadecimal, so a 12- or 24-word phrase must be converted first, a step NGRAVE says should be done offline. NGRAVE states the plates resist fire up to 1375°C, water and corrosion. For other approaches to steel backups, see how to back up a seed phrase on metal.