What is TOTP? Meaning, codes and the 30-second timer

TOTP stands for Time-Based One-Time Password. It is the short-lived code you see in an authenticator when a service asks for a second sign-in step.

A key and a clock

The authenticator and the service share a setup key. Both use it with the current time to calculate a code. A typical setup displays six digits and starts a new interval every 30 seconds. Other settings are possible, so the service’s configuration is what matters.

The setup key is not the sign-in code

A setup key is the longer text you add when configuring an authenticator. The short number displayed afterwards is the code you enter when signing in. In 2FAOrbit, paste the setup key into “Authentication key”; copy the large number from the orbit into the service’s sign-in form.

Read the orbital timer

The highlighted arc shows the time left in the current interval. When it reaches the end, the next code appears. If only a second or two remains, wait for the next interval before copying. Your device clock should be set automatically.

Try it without an account

The authenticator starts with a clearly marked public example. Change the key to use your own setup, or choose “Try example” to return to the demonstration. The demo is for exploring the interface, rather than signing in to a real account.

Technical reference: RFC 6238: TOTP.