The official site refused the connection at verification time: the price (~€285) comes from a third-party source (WalletScrutiny), not the official store.
For this reason this service does not appear in our rankings, comparator or comparison pages: it will once its terms can be verified against a dated official document.
Keepser
Keepser Group
Keepser is a cold wallet from France's Keepser Group in a contactless NFC card format: you tap the card against the back of an NFC phone to operate it, with no cables. More than a plain crypto wallet, it is a digital vault: it stores up to 100 "Keeps" — private keys, seed phrases, passwords, bank cards, sensitive data — protected by RSA 4096 key management and additional security layers (including a geofencing feature on the Pro+ model). It is multi-asset and designed to be compatible with the main crypto platforms via app and plugin. At the time of verification the official server was not reliably reachable: the price (~€285 for the Pro bundle, from third-party source WalletScrutiny) is given as an estimate and the entry is flagged as partial data. Transparency note: WalletScrutiny reports that the companion app has access to the keys, a security model to weigh carefully. Firmware/software is not open-source.
Data & conditions
| Fund custody | Self-custody (funds in your control) |
|---|---|
| Type | Hardware (cold storage) |
| Source code | Closed-source |
| Recovery | Archiviazione di chiavi/seed sulla carta NFC (fino a 100 Keeps); nessuna seed BIP-39 standard generata dal dispositivo |
| Bitcoin-only | No |
| Supported chains | Bitcoin, Ethereum, ERC-20 |
| Price | €285 |
| Secure element | No |
| Air-gapped | No |
| Connectivity | NFC |
| Built-in swap | No |
| Built-in staking | No |
| Segment | B2C |
| MiCA / License status | Nessuna (hardware wallet self-custody) |
Plans & pricing
Strengths
- Contactless NFC card format with no cables or battery; multipurpose vault handling up to 100 keys/seeds/passwords beyond crypto; RSA 4096 key management; EU-based company (France).
- Self-custody: funds stay in your wallet — the platform cannot touch them.
- No KYC: usable without identity verification.
Weaknesses
- Closed-source software/firmware, not independently verifiable; per WalletScrutiny the companion app has access to the keys, a security model to weigh; unstable price and availability — official server unreachable at verification, price (~€285) estimated from a third-party source (partial data).
- Closed source: no way to verify what it does with wallet and data.
Verdict
Score 3.6/5, average profile. In its favour: contactless NFC card format with no cables or battery; multipurpose vault handling up to 100 keys/seeds/passwords beyond crypto; RSA 4096 key management; EU-based company (France). The trade-off to weigh: closed-source software/firmware, not independently verifiable; per WalletScrutiny the companion app has access to the keys, a security model to weigh; unstable price and availability — official server unreachable at verification, price (~€285) estimated from a third-party source (partial data).
On the Sovereignty lens the score is 3.5/5 (solid): the strength is fund control (5.0/5), while trustless / auditability (0.0/5) is the weak link.
Promp's editorial rating based on real fees and net annual cost. Promp reviews third-party products independently.
"Sovereignty" rating: score computed on privacy/anonymity (30%), fund control (20%), censorship resistance (20%), trustless/auditability (20%) and costs (10%). Same data, different weights.
FAQ
How much does a Keepser cost?
The indicative price of the Keepser Pro bundle is about €285 (third-party source WalletScrutiny), with the Pro+ in a higher tier. At the time of verification the official Keepser server was not reliably reachable, so the figure is an estimate and the entry is partial data.
How does the Keepser work?
It is a contactless NFC card: you tap it against the back of an NFC-capable phone (Android from KitKat 4.4 up) to read and write data, via the Keepser app and a computer plugin. It has no cables or battery.
What can I store in a Keepser?
Up to 100 "Keeps": crypto private keys and seed phrases, but also passwords, bank card details and other sensitive data. It is designed as a multipurpose digital vault rather than a single-coin wallet.
Sources
- Official service page Form factor · NFC · Multi asset Data verified on Aug 3, 2026
- walletscrutiny.com NFC · Numero keeps · Tecnologia Data verified on Aug 3, 2026