Card-shaped hardware wallets have a special appeal: they hide in any billfold, and cost far less than the chunky USB sticks of yesteryear. But trust is everything. Keycard Shell burst onto the scene in April with a radically open design, while Tangem Wallet has established itself as a card solution. Below you’ll see where they truly diverge - so you can decide (and, if you’re convinced, grab a Keycard Shell before batch #1 is gone).

TL;DR (90-second read)

Keycard Shell turns an EAL 6+ Keycard into an air-gapped signer with its own screen, keypad, camera and optional USB-C. Works out-of-the-box with MetaMask, Rabby, UniSat, BlueWallet, Sparrow, Backpack, Status and more. Supports every EVM chain (Ethereum, Layer 2s like Arbitrum) plus Bitcoin/Lightning today.
Tangem is a phone-centric NFC card using a Samsung S3D232A secure element. It talks only to the Tangem mobile app but can hold keys for 85+ blockchains inside one card.
Quick verdict: If transparency and multi-wallet compatibility matter most, choose Keycard Shell. If you want the lightest tap-and-go card with zero firmware tinkering, Tangem excels.

Ready to commit? Pre-order Keycard Shell now - shipping begins October 2025.

Specification Sheet

Feature	Keycard Shell	Tangem Wallet
Secure element	EAL6+ JavaCard	EAL6+ Samsung S3D232A
Firmware	100 % MIT-licensed	Closed; audited
Display / Input	1.8″ OLED + keypad	None — relies on phone
Connectivity	NFC, QR (ERC-4527 / UR 2.0), optional USB-C	NFC only
Backup model	Unlimited Keycards, PIN-protected, duress PIN	Clone to 2–3 sibling cards during setup
Coins supported	Bitcoin (SegWit & Taproot), Lightning, all EVM chains & ERC-20/NFT standards	85+ networks from Bitcoin to zkSync (list in app)
MSRP (June 2025)	€ 99 (Shell + 2 Keycards)	$ 59 (2-card) / $ 79 (3-card)

Deep-Dive: Security Architecture

Keycard Shell

Signing inside the secure element - the private key never leaves the Keycard; the STM32 microcontroller stores only public information (public keys, tx history etc). (keycard.tech)
Non-upgradable secure applet - no “surprise” firmware updates can ever exfiltrate keys. (keycard.tech)
True air-gap - QR in, QR out; USB can be physically disabled. (keycard.tech)
Trusted display - the OLED shows the exact address & amount before you press OK, thwarting ByBit-style malware that tricks phone-only signers. (keycard.tech)
Duress PIN - unlocks a decoy HD path so you can hand attackers an empty wallet. (keycard.tech)

Tangem

Blind signing - no on-card screen; users trust the phone screen, so a compromised handset can swap targets invisibly.
Closed firmware - audits exist, but researchers still found a genuine-check bypass in 2024 that allowed counterfeit cards to masquerade as real ones until patch 5.18.3. (ledger.com)
Seed-phrase marketing - Tangem calls itself “seed-less,” but that simply means keys are generated on-card and never exported as BIP-39 words. The cryptographic seed still exists inside the chip.
Backup - during first activation, the key can be cloned to two more cards; you cannot add a third later without re-keying the wallet.

Day-to-Day UX

Step	Shell	Tangem
On-boarding	Insert Keycard → set main & duress PINs → scan pairing QR in any WalletConnect 2.0 wallet (~4 min)	Install Tangem app → tap card → choose access code → tap backup cards (~6 min)
Signing flow	Scan QR / tap NFC → verify on OLED → press OK	Open app → phone shows details → tap card
Speed (BTC 2-in PSBT)	~300 ms	~350 ms

Ecosystem & Integration

Shell works with MetaMask, Rabby, UniSat, Backpack, BlueWallet, Specter, Sparrow, imToken and more thanks to open Java, Swift, Go and Web SDKs. (keycard.tech, keycard.tech)

Building wallet support or experimenting with custom applets? Use an unfused Keycard for developers as your test card.

Tangem works only through the Tangem iOS / Android app today; desktop WalletConnect is “road-mapped” for Q4 2025. (tangem.com)

Physical Design & Durability

	Shell	Tangem
Chassis	Polycabornate body, rubber keypad + PVC (Keycard)	Laminated PVC
Water/Dust	Splash-proof	IP68 (1 m, 30 min)
Power	Replaceable BL-4C Li-ion (~3 months per charge)	Passive, battery-less
Thickness	9 mm (with Shell), and 0.8 mm Keycard	0.8 mm

Pricing & Availability

Product	What you need	Ship date
Keycard Shell – € 99 bundle	1 Shell + 2 Keycards; extra cards € 25 each	October 2025 pre-orders open now (keycard.tech)
Tangem 2-pack – $ 59	nothing else required	In stock online

Pros & Cons

Keycard Shell

✔ Open hardware & firmware
✔ Works with many major wallets via QR, and card-only via NFC if needed
✔ Trusted display, QR air-gap, USB kill-switch
✔ Unlimited card backups, duress PIN
✖ Thicker device, needs occasional charging
✖ No Solana support yet

Tangem

✔ Light, waterproof, no battery
✔ Handles 80 + networks in one card
✖ Phone-dependent “blind” signing
✖ Closed firmware; seed-logging vulnerability (tangem.com); genuine-check flaw (ledger.com)
✖ Single-app ecosystem

Who Should Choose What?

Persona	Pick Shell if…	Pick Tangem if…
Hardcore crypto enthusiast	You want to trust every line of code	You’re okay trusting 3rd-party audits, even with historic security issues
Multi-wallet power user	You juggle MetaMask, Sparrow, BlueWallet, imToken etc.	You are fine with one single mobile app.
Minimalist traveller	You need on-device address confirmation in cafés; and cards optional	You are fine with a display-less card but more chains supported.

Road-map Snapshot

Shell public GitHub shows active issues for multisig PSBT, EIP-4337 bundler support, and Lightning QR signing. (keycard.tech)

Tangem promises Bluetooth pairing and a desktop companion by Q4 2025. (tangem.com)

FAQ

Does Keycard Shell force me to write a seed phrase?
Yes. You export a BIP-39 phrase, but backing up two or more Keycards allows you to burn your unencrypted paper backup. (keycard.tech)

What if I lose the Shell but still have my Keycard?
Buy another Shell or even use any NFC phone or USB-reader connected to a laptop running Status wallet (open-source, too) - the keys stay on the card.

Can I add more Tangem backup cards later?
Unfortunately not; cloning is only allowed during the first activation. (Tangem Help Center). (tangem.com)

Final Verdict

If you value verifiable security, display-level confirmation, and wallet freedom, Keycard Shell is the clear choice - and its € 99 bundle feels modest given the extras. Tangem stays appealing for travellers who just want one indestructible card and don’t mind a walled-garden app.

🔒 Ready to secure your stack? Pre-order Keycard Shell today and lock in the early-bird pricing (includes 2 Keycards, ships October 2025).

Happy stacking - and stay safe out there!