Last year, I got a security alert that someone tried to log in to one of my accounts from halfway across the world. The hacker managed to get my password, but, fortunately, they didn’t have the second thing they needed: a security code sent to my phone.
That was the moment I really understood the value of two-factor authentication (2FA). Without it, I would’ve been locked out of my account, watching helplessly as a stranger rifled through my personal information and sensitive data.
To avoid becoming part of the roughly 600 million cyberattacks that occur daily worldwide, here’s everything you need to know about two-factor authentication and how to set it up.
Table of contents:
What is 2FA?
Two-factor authentication is a security measure that requires two different methods (or factors) to verify your identity before granting access to an account. It’s also referred to as 2FA or two-step verification.
How does 2FA work?
Two-factor authentication works by asking for two different kinds of proof to confirm that you are who you say you are. Think of it like a nightclub bouncer who checks both your ID and stamps your hand—except way less intimidating and with better lighting.
The three most common kinds of proof or authentication factors are:
-
What you know. This is usually the first thing you enter when trying to log in to an account. It includes passwords, PINs, and security questions.
-
What you have. This includes SMS authentication codes and push notifications, time-based tokens generated by authenticator apps, and hardware security keys.
-
Who you are. This includes biometric data, including fingerprints, facial recognition, and retinal scans. Unless someone’s pulling off a full Mission: Impossible mask swap, these markers are nearly impossible to replicate or steal, making them highly secure.
While it’s not officially recognized as an authentication factor, some systems also use location-based authentication to verify your identity. For example, if you’ve never visited Boston and someone is trying to access your account from there, your app might flag this and notify you to confirm it’s really you trying to log in.
Why is 2FA important?
Typically, when you log in somewhere, you enter your username and password. That’s single-factor authentication. It relies on just one piece of information—usually your password—to prove you are who you say you are.
But the problem is that passwords can be weak, reused, or guessed—especially if your password is “password” or the name of your dog, who also happens to be plastered all over your socials.
Two-factor authentication strengthens your digital security by adding a second layer to confirm your identity. Even if someone manages to get your password, they still need something else—like a code sent to your phone—to access your account.
Think of it like locking your front door (single factor) and then needing a keycard (second factor) to get inside. One layer alone is easily broken. Two layers make it much harder.
Can you add even more layers? Yes, you can. It’s called multi-factor authentication.
Two-factor authentication vs. multi-factor authentication
Two-factor authentication is not the same as multi-factor authentication. Here’s how the two differ:
-
Two-factor authentication (2FA): This is an authentication system that requires only two factors to prove your identity.
-
Multi-factor authentication (MFA): This is an authentication system that requires two or more forms of verification.
So all 2FA is MFA, but not all MFA is 2FA.
In reality, most of us will only ever use two factors—a password and a code or app. However, in high-security environments, such as banks and large companies, systems may require three or more factors.
Benefits of two-factor authentication
Nobody wakes up thinking, “You know what sounds fun? Adding more steps to my logins.” But the mundanity of setting up 2FA sure beats having to text your family and friends to warn them not to open the “Sponsor my walk-a-thon” email a hacker sent from your account.
Here are other reasons why you should incorporate 2FA in your digital security stack.
-
Reduced risk of unauthorized access. The second factor in two-factor authentication makes it extremely difficult to gain unauthorized access, keeping your personal information, accounts, and data much safer from online threats.
-
Enhanced protection against phishing attempts. Phishing scams trick you into handing over your password without you knowing. But even if you accidentally enter your password on a fake website, scammers still can’t access your real account without your phone or authentication app.
-
Quick recovery from compromised accounts. If someone steals your password, two-factor authentication adds a crucial layer of defense because they still need your trusted device to get in. That gives you a chance to step in, reset your password, and check for suspicious activity before any real damage happens.
-
Compliance with security best practices. If you’re handling sensitive data—for example, financial information, customer accounts, or your high school fan fic archive—2FA is often a requirement. Many workplaces and platforms expect you to use 2FA to meet compliance standards and safeguard your users and yourself.
-
Increased peace of mind. 2FA gives you a sense of control and reassurance, allowing you to go about your day without the nagging fear that your accounts could be easily compromised.
Types of two-factor authentication
Here are the most common types of two-factor authentication used to secure accounts.
SMS-based authentication
This is likely the 2FA type you’re most familiar with. It’s the one where you receive a text message with a six-digit code to enter into the site or app you’re trying to log in to. It’s simple and works on any phone—even your 2005 Nokia.
But cybercriminals can still hijack your phone number (called SIM swapping) to intercept these messages—the same way they did to former X/Twitter CEO Jack Dorsey. That’s why many security experts recommend using authenticator apps over SMS whenever possible.
Authentication apps with time-based one-time passwords (TOTPs)
TOTPs are codes (usually six digits) generated by an authenticator app, with the codes refreshing every 30 or 60 seconds. TOTPs are considered more secure than SMS verification since they’re generated locally on your device. You just need to open the app to get the code you need, and you can get codes for any number of apps on one authenticator app.
Push-based authentication
Instead of typing a code, push-based authentication involves receiving a push notification that asks you to approve or deny a login attempt.
Hardware security keys or tokens
These are small physical devices, like the YubiKey or Google Titan Security Key, that generate one-time codes or have built-in buttons for approving logins. Many options plug directly into your computer or phone for even faster, phishing-resistant logins.
Hardware security keys or tokens offer even stronger security compared to authenticator apps because they don’t rely on your phone or network.
Biometric authentication
Modern devices and apps offer biometric authentication—for example, fingerprint scanners and facial recognition—as a type of 2FA. The biggest drawback is that biometrics can’t be changed if compromised, and some methods can be fooled with high-quality photos or recordings. But advanced systems like Apple’s Face ID or Windows Hello include sophisticated anti-spoofing protections to minimize these risks.
How to enable 2FA on popular apps
Setting up two-factor authentication varies depending on the system you’re using. Here’s how to enable 2FA on the most popular apps you likely already use:
What happens if you lose access to your 2FA device?
Because two-factor authentication usually relies on using a secondary device, there’s a risk of losing access to your 2FA method if you lose that device. If that’s the case, or you’re having problems with your authenticator app, it’s going to take more work to verify your identity.
Here’s what the process might look like depending on the method you chose as your second authentication factor.
For accounts using SMS verification
Let’s say you lose your phone but still have access to your phone number (through your carrier or service provider). You can transfer your number to a new device or SIM card. Once that’s set up, you’ll resume receiving SMS or text messages—including 2FA codes.
If you don’t have access to your number, contact your mobile provider and have them disable your lost phone number and then port the number to your new phone.
For accounts using an authentication app
Authentication apps usually give you a set of backup or recovery codes. For example, when setting up Google’s 2-step verification, it’ll generate a list of backup codes.
Copy the recovery codes and store them in a safe place—whether that’s a physical safe or a virtual one, like a password manager app. This way, if you lose your device, you can use these codes to get back into your accounts.
If you lose both your device and your backup codes, recovery can be a pain and may involve contacting the platform’s customer support to verify your identity.
Best practices for two-factor authentication
Here are a few best practices to help you get the most out of 2FA without adding unnecessary headaches.
Use authenticator apps over SMS
For everyday accounts, using SMS authentication is fine. But for sites that deal with sensitive information—for example, banking details or customer data—you should use an authenticator app or physical security key. Plus, if you travel frequently or work in areas with limited cell service, authenticator apps and hardware keys are safer since they work offline and don’t depend on your mobile network.
Store backup codes securely
Store your backup codes in a secure location separate from your mobile phone so you can access your accounts if your device is ever stolen.
Enable 2FA on email accounts first
Your email address is the key to everything—Netflix, Instagram, the Tumblr account you haven’t accessed since 2012. If your email gets hacked, every other account is vulnerable since password reset emails will come into that email account.
That’s why it’s critical to set up 2FA for your email account. From there, work your way down the list: financial accounts, social media, and any other services that hold sensitive information.
Consider a password manager with built-in 2FA support
Password apps like 1Password and Bitwarden can store your login credentials and generate 2FA codes right inside the app. This way, you can autofill both your password and 2FA code in one go when logging in. It’s ridiculously convenient.
Keep your recovery info up to date
Do a regular audit of your recovery info. This includes making sure that your backup email and phone number are up to date, and that the answer to “My favorite dog’s name” is still “Leroy.”
The best authenticator apps
Authenticator apps aren’t exactly exciting, but they do a lot of heavy lifting behind the scenes. The good news: you’ve got options. Whether you want something simple and straightforward or a tool that works across all your devices with backups baked in, there’s an app for that. Here are a few of the best authenticator apps to consider.
Google Authenticator (iOS and Android)
Best for: Multiple mobile devices with Google accounts
Google Authenticator is quick to set up and straightforward to use. To add new sites you want to secure, tap the + icon in the bottom-right corner, and then follow the prompts to set up your 2FA. You can also export or import accounts to and from other devices with the Google Authenticator.
Once you enable the backup feature, Google Authenticator syncs your data with any device where you’ve logged in with the same Google account. To avoid sync issues, ensure the authenticator app on all your devices is up to date.
Authy (iOS, Android, MacOS, Windows, and Linux)
Best for: Multi-device sync and backup
Authy works on your computer and phone, with an account that you can move to a new device when you upgrade. It comes with a backup key that lets you sync and back up accounts, which is especially handy if you ever lose your device.
You can also enter your login codes in a widget on your phone for one-tap access and on your desktop so that you can log in without your phone.
Microsoft Authenticator (iOS and Android)
Best for: Microsoft ecosystem users
While Microsoft Authenticator works with major platforms, it’s particularly useful if you live in Windows, Microsoft 365, and Azure accounts. You can set up different types of authentication methods, including code generation, push notifications, and biometrics.
Duo (iOS and Android)
Best for: Enterprise and corporate security
Duo is an enterprise security tool that manages company logins and secures devices. As an account administrator, you can set custom security policies based on an employee’s role, location, or device. The app also comes with reporting systems that let you track suspicious security behaviors so you can respond to risks in real time.
Bitwarden Authenticator (iOS and Android)
Best for: Open source security
Bitwarden Authenticator is an authenticator app that generates TOTPs—it’s not the same as Bitwarden’s Password Manager. So, even if you don’t use the password manager, you can still install and use the authenticator app. It’s fairly easy to set up, and you can export your keys or accounts. Although it doesn’t do much yet, you can expect features like account recovery and push-based 2FA down the line.
1Password (iOS, Android, macOS, Windows, and Linux)
Best for: All-in-one security management
1Password is a password manager that also includes 2FA support. You can scan 2FA QR codes from 1Password’s mobile or desktop apps and get your login information and 2FA codes synced to all of your devices.
Note: While it’s super convenient to keep your passwords and 2FA codes in one place for most accounts, don’t use the password manager to store the code for your 1Password account itself.
Keep your accounts secure with 2FA
Two-factor authentication remains one of the simplest and most effective ways to protect your online accounts. Sure, it adds a bit of extra friction when you sign in—an extra code here, a push notification there—but that extra step is what stands between your data and someone hacking it.
Is it perfect? No. Sophisticated phishing attacks can still find clever ways around it. But in most cases, 2FA stops threats in their tracks. So if you’re still relying on passwords alone, now’s the time to make the switch. You don’t want to be the person panic-changing passwords in the middle of the night because some random site you forgot you had an account with got hacked. Set up 2FA once so future you can breathe a little easier.
Related reading: