Hardware wallet review · 2026
NGRAVE · Brussels, Belgium · Founded 2018
NGRAVE ZERO review: the coldest wallet money can buy.
The NGRAVE ZERO is a fully air-gapped hardware wallet with an EAL7-certified secure operating system, a big touchscreen, and a steel backup that survives fire and water. It’s also the most expensive mainstream wallet on the market, and that price is the whole debate. We dug into the security architecture, the LIQUID app, coin support, and how it stacks up against Ledger, Trezor, and Keystone.
By Gaurav Agarwal · · ● Tested against 4 rival wallets
Our verdict
SCORED ON SECURITY, BACKUP, COIN SUPPORT, APP QUALITY, AND VALUE
The ZERO earns its “coldest wallet” tagline. A true air-gap, a certified secure OS, and the GRAPHENE steel backup add up to one of the most isolated cold-storage setups you can buy. The catch is the price and the polish: $398 is steep, the firmware is largely closed, and the LIQUID app’s QR scanning frustrates power users. Buy it if security and a bombproof backup matter more than price or daily DeFi. If you want the same air-gap for less, the Keystone 3 Pro is the obvious rival.
+ Best for
- Long-term holders parking a large balance in cold storage
- Buyers who want a certified secure OS and a steel backup
- Anyone set on a no-radio, fully air-gapped device
- People who rarely transact and value isolation over speed
− Skip it if
- You’re an active DeFi or dApp user who signs daily
- You want open-source firmware you can audit
- You need native ADA, ATOM, or DOT support
- You’re on a budget, since the Keystone 3 Pro costs far less
NGRAVE ZERO specifications
| Price | $398 wallet · $498 COMBO PACK with GRAPHENE |
| Released | 2021 · still NGRAVE’s flagship in 2026 |
| Secure element | EAL5+ certified secure element chip |
| Secure OS certification | EAL7-certified secure operating system |
| Connectivity | None for signing · no BT / Wi-Fi / NFC / 4G · USB-C is charge + firmware only |
| Display | 4-inch (101.6 mm) color touchscreen · 480 × 800 px |
| Battery | 1200 mAh rechargeable via USB-C |
| Backup | GRAPHENE two-plate stainless steel · fireproof + waterproof |
| Supported assets | ~1,000 · BTC, ETH, SOL, XRP, AVAX, POL, BNB + all ERC-20 |
| Open source | Largely closed · partial open-sourcing pledged (not SE/OS) |
The honest take
What works, and what to watch.
+ What works
- Genuine full air-gap, with no USB data, Bluetooth, Wi-Fi, or NFC
- The only consumer wallet with an EAL7-certified secure OS, plus an EAL5+ secure element
- GRAPHENE two-plate steel backup is one of the best recovery systems made
- Multi-source entropy from the chip, your fingerprint, and ambient light
- Tamper-evident casing that wipes keys if the device is opened after setup
- Large, readable touchscreen makes reviewing transactions clear
- Strong academic pedigree, built with imec and KU Leuven’s COSIC group
− What to watch
- Most expensive mainstream wallet at $398, or $498 for the combo
- Firmware is largely closed-source, so independent audits are limited
- No native Cardano, Cosmos, or Polkadot support
- No native WalletConnect, so DeFi runs through MetaMask or Rabby
- The LIQUID app draws complaints, and QR scanning can be finicky
- QR signing is slower than plugging in a cable for frequent transactions
- The Perfect Key setup ritual has a real learning curve
Security architecture
6 layers that make it cold.
NGRAVE’s whole pitch is isolation. Here’s how each layer holds up once you look past the marketing, including where the open-source story falls short.
True air-gap
No Bluetooth, Wi-Fi, NFC, or 4G. The USB-C port charges the device and loads firmware only, and it blocks data transfer otherwise. Every signature happens offline and moves by QR code, so private keys never touch a connected device.
EAL7 OS + EAL5+ element
The ZERO runs an EAL7-certified secure operating system, the highest assurance level, on top of an EAL5+ secure element chip. People shorthand this as “the EAL7 wallet,” but the precise claim is an EAL7 OS paired with an EAL5+ secure element.
Perfect Key entropy
Key generation blends three sources: the chip’s hardware true-random number generator, your fingerprint, and a sample of the ambient light in your room. The goal is that even NGRAVE can’t reconstruct your key.
GRAPHENE steel backup
A two-plate stainless steel system. One plate holds a device-unique pattern, the other holds your key data, and neither plate reveals anything on its own. It’s rated fireproof and waterproof, and you only need the plates plus any new ZERO to recover.
Biometrics + anti-tamper
A rear fingerprint reader unlocks the device and feeds entropy at setup. The casing is tamper-evident, internal sensors wipe the keys if the device is physically opened after setup, and repeated failed logins also trigger key erasure.
Firmware openness
This is the weak spot. The firmware is largely closed-source. NGRAVE keeps a public GitHub repo and has pledged to gradually open-source parts of it, except the secure element and OS, but the ZERO isn’t fully auditable the way Trezor or BitBox02 are.
How it works
Keys, QR signing, and the LIQUID app.
Key generation
The Perfect Key, not 24 words.
NGRAVE swaps the standard 24-word seed for a “Perfect Key,” the 64-character hex form of your 256-bit master seed. It’s mathematically the same as a BIP39 mnemonic, just written differently.
Setup is gamified. A key streams in real time, you hit “freeze” to lock the entropy, and you can “shuffle” groups for extra randomness. You set a PIN first, which can double as a passphrase. It’s clever, but slower than jotting down a word list.
Signing and LIQUID
Two-way QR, never a cable.
You build a transaction in the LIQUID phone app. It shows a QR code, the ZERO scans it with its camera, you review and approve on the touchscreen, the ZERO shows a signed-transaction QR, and LIQUID scans it back to broadcast.
It works, and it keeps the keys offline. But LIQUID has drawn critical Play Store ratings, and the QR scanning can be fiddly in poor light. App quality is the weakest link in day-to-day use, so frequent traders should weigh that.
Coins and chains
Around 1,000 assets, with real gaps.
Reviewers cite “1,000+ assets,” and the majors are covered well. Native support includes BTC, ETH, SOL, XRP, AVAX, POL (Polygon), BNB, LTC, BCH, DOGE, XTZ, XLM, and ZEC, plus all ERC-20 tokens and MultiversX ESDT tokens. If you’re buying it to hold Bitcoin and Ethereum for the long haul, you’re well served. New to Ethereum? Our guide to buying ETH walks through the on-ramp.
− Where coverage falls short
- No native Cardano (ADA), Cosmos (ATOM), or Polkadot (DOT)
- NFTs are supported on Ethereum only
- No native WalletConnect in LIQUID
- DeFi and extra EVM chains need MetaMask or Rabby as the signer
+ What you can still do
- Stake, swap, and bridge while signing offline through third-party apps
- Pair with MetaMask or Rabby to reach dApps indirectly
- Hold the full ERC-20 token range
- Native ETH staking in LIQUID is on the roadmap
NGRAVE ZERO vs the competition
| Wallet | Price | Air-gap | Certification | Open source | Best for |
|---|---|---|---|---|---|
| NGRAVE ZERO | $398 | Full (QR) | EAL7 OS + EAL5+ SE | Mostly closed | Maximum cold-storage isolation |
| Ledger Stax / Flex | ~$249–399 | No (USB/BT) | EAL6+ class SE | Closed | Daily DeFi, broad chain support |
| Trezor Safe 5 | ~$169 | No (USB) | OPTIGA Trust M SE | Fully open | Open-source purists |
| Keystone 3 Pro | ~$149 | Full (QR) | Triple secure element | Largely open | Same air-gap for less |
| BitBox02 | ~$150 | No (USB) | Dual-chip design | Fully open, audited | Audited, budget-friendly |
Pricing
What it costs, and what’s in the box.
ZERO
The air-gapped device, USB-C cable, and a quick-start guide. You’ll want a steel backup on top of this.
COMBO PACK
The wallet plus the GRAPHENE two-plate steel backup. This is NGRAVE’s headline bundle and the one most buyers should pick.
GRAPHENE
The steel backup on its own, if you already own a ZERO. Fireproof, waterproof, and split across two plates.
That makes the ZERO the most expensive mainstream consumer hardware wallet, a point nearly every reviewer raises. You’re paying for the certification, the build, and the backup, not for broader coin support.
The buying decision
Who should buy it, and who shouldn’t.
The ZERO is a specialist tool. It’s excellent for one job and the wrong choice for another. Here’s the split.
Buy it if
You’re a long-term holder or high-net-worth investor who wants maximum isolation, a certified secure OS, and a steel backup that survives a house fire. You rarely transact, you want a no-radio device, and you’re fine paying a premium for it. The big touchscreen also makes reviewing transactions far clearer than tiny-screen dongles.
Skip it if
You’re an active DeFi or dApp user, since QR signing is slow and native DeFi is absent. Open-source purists should pick Trezor or BitBox02. Multi-chain holders who need ADA, ATOM, or DOT natively will hit walls. And budget buyers get the same air-gap from the Keystone 3 Pro for far less. Want options first? Start with our best hardware wallets guide.
FAQ
7 questions buyers ask about the NGRAVE ZERO.
Is the NGRAVE ZERO worth it?
For long-term holders with a large balance, yes. You get a fully air-gapped device, an EAL7-certified secure OS, an EAL5+ secure element, and the GRAPHENE steel backup. At $398 it’s the priciest mainstream wallet, so frequent traders and budget buyers get better value from the Keystone 3 Pro, which uses the same QR air-gap for about a third of the price.
Is the NGRAVE ZERO really air-gapped?
Yes. It has no Bluetooth, Wi-Fi, NFC, or 4G, and the USB-C port handles charging and firmware updates only. Every transaction is signed offline and moved between the ZERO and the LIQUID app through QR codes the two devices scan from each other’s screens.
NGRAVE ZERO vs Ledger — which is better?
They solve different problems. Ledger supports more chains, smoother DeFi, and costs less, but it signs over USB and Bluetooth and runs closed firmware. The ZERO is fully air-gapped, carries an EAL7 secure OS, and has a better physical backup, but it’s pricier and supports fewer chains natively. Pick Ledger for daily DeFi, the ZERO for maximum cold-storage isolation. Our hardware wallet guide compares both.
Is the NGRAVE ZERO open source?
Mostly no. The firmware is largely closed-source. NGRAVE has pledged to gradually open-source parts of it, except the secure element and secure OS, and keeps a public GitHub repo, but as of 2026 the device isn’t fully auditable the way Trezor or BitBox02 are. Open-source purists should choose one of those instead.
What coins does the NGRAVE ZERO support?
Around 1,000 assets, including BTC, ETH, SOL, XRP, AVAX, POL, BNB, LTC, BCH, DOGE, XTZ, XLM, ZEC, and all ERC-20 tokens. There’s no native Cardano (ADA), Cosmos (ATOM), or Polkadot (DOT). NFTs are Ethereum-only, and there’s no native WalletConnect, so you reach dApps by pairing the ZERO with MetaMask or Rabby.
How much does the NGRAVE ZERO cost?
The ZERO wallet alone is $398. The COMBO PACK, which adds the GRAPHENE steel backup, is $498. GRAPHENE on its own is about $148. That makes the ZERO the most expensive mainstream consumer hardware wallet.
Is NGRAVE legit and safe?
NGRAVE is a Belgian security company founded in 2018, built with research partners including imec and KU Leuven’s COSIC group. The ZERO carries an EAL7-certified secure OS and an EAL5+ secure element, with tamper-evident casing and key-wipe on physical intrusion. No product recall or confirmed key-extraction exploit has surfaced, so its record is clean to date, though no wallet should be called unhackable.
The bottom line
The NGRAVE ZERO is the most isolated cold-storage wallet you can buy, and it backs that up with a certified secure OS and the best steel backup on the market. The price is the honest trade-off: at $398 you’re paying a premium for security and build, not for coin breadth or DeFi. If you’re a long-term holder who wants the coldest setup possible and you’ll rarely transact, it earns its 4.4/5. If you want the same air-gap for less, look at the Keystone 3 Pro. If you live in DeFi or need open code, look elsewhere.
Buy the NGRAVE ZERO →Editorial note: prices, certifications, and coin support were checked against NGRAVE’s official store and support documentation in June 2026 and can change. We don’t quote a specific firmware version here because the current build wasn’t independently confirmed at publication. Our score reflects independent testing and public sources, not input from NGRAVE. This is research, not financial advice.
Related reading
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- Best hardware wallets for Bitcoin (the full lineup, from air-gapped to budget picks).
- Best crypto wallet apps (software wallets to pair with cold storage).
Buying & trading
- How to buy Ethereum (the on-ramp before you move ETH to cold storage).
- Best crypto exchanges (where to buy coins before self-custody).
