Updated October 13, 2026 · ShieldCue Editorial Team
Thetis vs OnlyKey
Thetis vs OnlyKey: the differences
| Compare |  Thetis | OnlyKey ReviewSee alternativesSee alternatives |
|---|---|---|
| Price | $24.99 to $49.99 | €49.95 |
| Protocols | FIDO2, FIDO U2F, WebAuthn, CTAP2, TOTP, HOTP | Fido2, U2f, Otp |
| Connectors | USB a, USB c, NFCCovers more | USB a, USB c |
| Biometric unlock | YesHas it | No |
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Key differences
- Protocols: only Thetis offers FIDO U2F, WebAuthn, CTAP2.
- Protocols: only OnlyKey offers U2f, Otp.
- Connectors: only Thetis offers NFC.
- Biometric unlock: only Thetis.
- Support channels: only OnlyKey offers Community.
- Founded is lower at Thetis: 2014 vs 2016.
Our verdict on each
Thetis
Thetis ties account safety to a small aluminum key you plug in or tap, which removes passwords but means the device must stay with you. The brand covers shoppers, employees and developers who want phishing resistant passkey logins across hundreds of supported email, shopping and work services.
OnlyKey
OnlyKey suits buyers who want a hardware key that handles passkeys, TOTP codes and password storage together, with open source firmware and a logging policy that keeps customer secrets off the vendor's side. The Duo costs €49.95 as a device, above Token2 and the Google Titan Security Key.
Score breakdown
| Area | Thetis | OnlyKey |
|---|---|---|
| Cost | Not confirmed | 8.0The Duo costs €49.95 and ranks 14 of 15 on price across the site. |
| Offer | 9.1Higher | 8.6 |
| Privacy | 8.5Higher | 8.0 |
Positions in our rankings
| Ranking | Thetis | OnlyKey |
|---|---|---|
| Hardware security keys | 12 of 18 | 8 of 18 |
Side by side, item by item
| Protocols | Thetis | OnlyKey |
|---|---|---|
| Fido2 | Yes | Yes |
| U2f | No | Yes |
| Otp | No | Yes |
| Connectors | Thetis | OnlyKey |
|---|---|---|
| USB a | Yes | Yes |
| USB c | Yes | Yes |
| NFC | Yes | No |
Sources behind this comparison
Thetis
- thetis.io: 9 facts, checked September 26, 2026
OnlyKey
- onlykey.io: 8 facts, checked September 26, 2026
Every fact side by side
| Fact | Thetis | OnlyKey |
|---|---|---|
| Pricing model | Budget | Not confirmed |
| Legal entity | Razzo Tech Corporation | CryptoTrust LLC |
| Headquarters | United States | United States |
| Founded | 2014Lower | 2016 |
| Support channels | Email, Help centre | Email, Help centre, CommunityCovers more |
Privacy tools
| Fact | Thetis | OnlyKey |
|---|---|---|
| Price from | Not confirmed | €49.95 |
| Free plan | Not confirmed | No |
| Platforms | Windows, MacOS, Linux, iOS, Android, Chrome | Windows, MacOS, Android, Linux, Chrome OS |
| Logging policy | Not confirmed | Zero knowledge: no customer keys or sensitive data stored by the company |
| Jurisdiction | US | US |
| Open source | Not confirmed | Yes |
Password managers
| Fact | Thetis | OnlyKey |
|---|---|---|
| Passkeys | Not confirmed | Yes |
| Encryption | Not confirmed | AES-256-GCM, PIN protected with wipe after 10 failed unlock attempts |
| Features | Not confirmed | TOTP |
Pros and cons
Thetis
Pros
- Pro Series combines USB A, USB C and NFC in one key
- Fingerprint option adds biometric touch to FIDO2 passkey logins
- Durable aluminum casing resists drops, bumps and scratches daily
Cons
- Protection depends on carrying and connecting a physical key device
- Coverage applies only to online services that support FIDO standards
- Narrow catalog focuses on authentication hardware rather than wider tools
OnlyKey
Pros
- Open source firmware, paired with a logging policy in which the company states it holds no customer keys or sensitive data.
- The Duo carries usb a and usb c in the same unit, so machines with either port are covered by the same purchase.
- It speaks fido2, u2f and otp and also handles totp codes, so the same key covers security keys, authenticator codes and passwords.
Cons
- Biometric unlock is no, which leaves the PIN and its wipe rule carrying the security of the device.
- The free plan is no, so the only route to the features is buying hardware at €49.95.
- The price runs above Token2 at €7 to €37 and the Google Titan Security Key at $30 to $35.
Who each suits
Thetis
Who it suits
- Shoppers securing email, shopping and financial accounts
- Business teams replacing passwords with phishing resistant logins
- Developers protecting repositories and smart contracts
Who should look elsewhere
- People seeking software only protection without hardware
OnlyKey
Who it suits
- People who want a physical key for passkeys and authenticator codes and who treat open source firmware as a requirement rather than a bonus.
- Mixed-port desks that need USB-C and USB-A covered by usb a and usb c in a single purchase.
- Buyers who would rather own the key outright and can accept a PIN instead of biometric unlock.
Who should look elsewhere
- Not for the tightest budget, since Token2 runs €7 to €37 against OnlyKey at €49.95.
- Not for people who expect to pick up a phone, because OnlyKey lists email, help centre and community as its support routes.
Questions about each
Thetis
What does Thetis sell?+
Thetis sells physical FIDO2 security keys that enable passwordless and phishing resistant logins. The devices plug into computers or tap by contactless connection for authentication. They help secure everyday logins with unique cryptographic keys instead of passwords.
What product ranges does Thetis offer?+
Thetis offers standard FIDO2 keys, contactless keys and fingerprint BioFP models for passkey use. The Pro Series combines USB A, USB C and NFC in one device. The range supports individual, business and developer authentication needs.
OnlyKey
What does an OnlyKey cost, and what do rivals charge?+
The Duo is priced at €49.95, and entry prices start at €49.95. The figure buys the hardware, so the outlay at entry is the outlay later on, and the device price is the only price on offer here. Cheaper rivals exist: Token2 runs €7 to €37 and the Google Titan Security Key runs $30 to $35.
Which protocols and passkey methods does it support?+
The protocol list is fido2, u2f and otp, and passkeys are supported as well. That lets the same device act as a passkey authenticator, a security key for a login prompt and an OTP token for codes. Password storage sits on the key too, so a login, a code and a saved credential are handled by the same purchase rather than by separate tools.