Support every user, everywhere

From online to offline, mobile apps to landlines to tokens. Users can have multiple devices and choose their method during login.

Duo Push Duo Mobile SMS Passcodes Phone Callback Hardware Tokens
Duo Push Duo Mobile Passcodes SMS Passcodes Phone Callback Hardware Tokens
Description Duo sends a login request to your phone. Just tap Approve to authenticate. Generate passcodes with Duo’s free mobile application. Receive a batch of passcodes via SMS. Duo calls your phone. Just press any key to authenticate. Use the passcode generated on your hardware token.
Platforms Duo Push platforms Duo Push platforms, as well as Palm, Windows Mobile, and J2ME/Symbian All phones with SMS All phones YubiKeys and all OATH-compliant tokens
Offline usage? Yes Yes
Store a batch for offline use
Additional cost? Always free for all customers.
We never charge for our mobile applications or authentication methods.
Phone calls and SMS messages use your account’s telephony credits.
Most paid accounts include 100 credits/user/mo.
Buy hardware tokens from us, or import your own for free.

Duo Push

Choose Duo Push to get a login request sent to your phone. Then just review the details and tap Approve to log in.

No phone calls to wait for or passcodes to type.

Learn more

Duo Mobile

Our free mobile application lets you respond to Duo Push notifications.

You can also generate one-time passcodes for login, even without an internet connection (great for airplanes!).

SMS Passcodes

Getting a passcode via SMS is an easy and straightforward way to authenticate.

Duo can also send a batch of passcodes, providing a fallback for times when your phone doesn’t have cell reception.

Phone Callback

Duo will call your cell phone, landline, or car phone. Just press a key to quickly authenticate.

It’s not sexy but it works!

Hardware Tokens

The 90’s called — they want their tokens back.

But seriously: Duo supports all 6- and 8-digit OATH-compliant tokens. Buy hardware tokens from us, or import your own for free.

We also support YubiKeys!