YubiKey vs SoloKey: Battle of the Open-Source vs Proprietary

YubiKey vs SoloKey: Which Security Key Should You Trust in 2025?

Hardware security keys have become the gold standard for protecting accounts from phishing, SIM swaps, and credential stuffing. In 2025, two of the most talked-about options are YubiKey and SoloKey—one proprietary and enterprise-focused, the other fully open-source and transparency-driven.

If you’re trying to choose between the two, this guide breaks down the real differences so you can pick the one that fits your security, trust, and compatibility needs.

What Are YubiKey and SoloKey?

YubiKey

A hardware key made by Yubico, known for:

• Rock-solid build quality

• Broad enterprise adoption

• Support for FIDO2, WebAuthn, OTP, Smart Card, and more

• Proprietary firmware (closed-source)

SoloKey

A hardware key created by SoloKeys.io, known for:

• 100% open-source firmware

• Transparent security model

• Affordable price

• Focus on community and trust-by-audit

• FIDO2/WebAuthn support

1. Security: Which Key Is More Trustworthy?

YubiKey Security

YubiKey uses a proprietary firmware, meaning you cannot inspect the source code.
However, they are:

• Used by Google, Microsoft, and top enterprises

• Highly audited

• Resistant to physical tampering

• Certified with security standards like FIPS 140-2

Bottom Line: Trust is placed in Yubico’s reputation and enterprise-level testing.

SoloKey Security

SoloKey’s firmware is fully open-source, making it:

• Transparent

• Auditable

• Verifiable by anyone

• Preferred by privacy enthusiasts and security researchers

They also use secure hardware with anti-tamper protections.

Bottom Line: Trust comes from open-source transparency, not secrecy.

2. Compatibility: YubiKey Still Wins Here

If you need maximum website and app compatibility, YubiKey leads the market.

YubiKey supports:

• Windows Hello

• macOS

• Linux

• Google accounts

• Microsoft 365

• GitHub

• AWS

• Okta

• 1Password

• Facebook

• Dropbox

• Salesforce

• Hundreds more

SoloKey works with all FIDO2/WebAuthn websites, but:

• Lacks full enterprise protocol support

• Isn’t as widely officially recognized

• Doesn’t support PIV/Smart Card or OTP modes

If your job involves identity access management or enterprise platforms, YubiKey is the safer bet.

3. Features: What Can Each Key Actually Do?

YubiKey Features

Supports multiple security modes:

• FIDO2

• WebAuthn

• U2F

• One-Time Password (OTP)

• Smart Card (PIV)

• OpenPGP

• SSH with hardware-backed keys

• Static Password Mode

This flexibility makes YubiKey the Swiss Army knife of authentication.

SoloKey Features

SoloKey primarily focuses on:

• FIDO2

• WebAuthn

• U2F

This keeps it simple and open-source but less multi-purpose.

4. Build Quality and Durability

YubiKey

Built like a tank:

• Waterproof

• Crush-resistant

• Heat resistant

• Keychain-friendly

These keys routinely last many years.

SoloKey

Still durable but:

• Lighter plastic

• Not as rugged

• Not meant for extreme wear-and-tear

Great for normal everyday use, but not the same industrial-grade finish.

5. Pricing: SoloKey Is More Budget-Friendly

ProductPrice RangeYubiKey 5 Series$50–$90+SoloKey$25–$45

If you’re buying multiple keys for backup, SoloKey offers solid value.

6. Privacy & Trust: Open-Source vs Proprietary

This is where opinions vary:

Why People Trust YubiKey

• Long history in cybersecurity

• Used by major companies

• Passed several third-party audits

• Proven track record preventing phishing attacks

Why People Trust SoloKey

• Fully open-source (no secrets)

• Anyone can inspect or compile the firmware

• Transparency = confidence

• Popular among free software supporters and cryptography researchers

If transparency matters more than mainstream adoption, SoloKey is appealing.

Which One Should You Choose?

Choose YubiKey If You Want:

✔ The most compatible hardware key
✔ Enterprise-level security
✔ Multi-protocol support
✔ Rugged durability
✔ Proven real-world adoption

Best for: professionals, system administrators, IAM engineers, businesses, Google/Microsoft ecosystems.

Choose SoloKey If You Want:

✔ Fully open-source firmware
✔ Lower cost
✔ Transparent and verifiable security
✔ A simple FIDO2/WebAuthn-only solution

Best for: privacy fans, developers, open-source advocates, budget-conscious users.

Final Verdict: YubiKey vs SoloKey

YubiKey wins on compatibility, features, and durability.
SoloKey wins on transparency, simplicity, and price.

Your choice depends on how you define “trust”:

• Trust the company? → go YubiKey

• Trust the open-source code? → go SoloKey

Both are excellent for strong 2FA and passwordless security in 2025.