SMS vs authenticator app vs security key: which 2FA should you use?
2 min read · Updated October 15, 2026
Security keys and passkeys offer the strongest protection, authenticator apps are the best everyday choice and SMS is the weakest but still better than no second factor. Use the strongest method each account supports, especially for email and financial accounts.
SMS codes
A text message with a code is easy to set up and needs no extra app. The downside is that phone numbers can be hijacked through SIM-swap fraud, and messages can sometimes be intercepted or phished.
Authenticator apps
These apps generate a new code every thirty seconds or so on your device. They do not depend on your phone number, so SIM-swap does not affect them. They are a good default, as long as you back up the setup so you can move to a new phone.
Is your login already in a leak?
Strong habits help most when you know which accounts are already exposed. Check your email address for free.
Security keys and passkeys
A hardware key or a passkey proves you are on the genuine site, which blocks most phishing attempts. They are the strongest option available to everyday users.
How to choose
- ✓Email, banking, crypto and work accounts: passkey or security key if supported, otherwise an authenticator app.
- ✓Everyday accounts: authenticator app.
- ✓Accounts that only offer SMS: use it rather than nothing.
Frequently asked questions
Is SMS 2FA better than nothing?+
Yes. It blocks most automated attacks using leaked passwords.
What if I switch phones?+
Move or re-enrol your authenticator app before wiping the old phone, and keep backup codes.
Do I need a hardware key?+
Not for most people. They are worth considering for high-risk accounts.
Stop guessing. Check your email in seconds.
The free Leakill check looks for your email address in known breach records and tells you whether it was exposed. If it was, an optional detailed report lists the incidents, dates, sources, the kinds of data involved and practical next steps. It is a one-off report, not a subscription.
A breach match is a warning signal, not proof that someone has access to your account today. No public database covers every breach, so a clean result lowers risk without guaranteeing safety.