TEST KEY
Use JBSWY3DPEHPK3PXP to test — this is the public RFC 6238 test vector. Never paste real 2FA secrets into online tools.
Free TOTP / 2FA Code Generator — Time-Based One-Time Passwords
Our free TOTP generator creates time-based one-time passwords from any Base32 secret key — the same codes produced by Google Authenticator, Authy and Microsoft Authenticator. Use it to test 2FA implementations, verify TOTP secrets and understand how time-based OTPs work. All computation uses the browser Web Crypto API — nothing is sent to a server.
How TOTP Works
TOTP (RFC 6238) generates a new code every 30 seconds using HMAC-SHA1 applied to the shared secret and the current 30-second time window. Both the authenticator app and the server compute the same value independently — no communication needed. This makes it resistant to replay attacks.
Security Warning
Never paste real 2FA secrets from live accounts into online tools. The test key shown (JBSWY3DPEHPK3PXP) is a publicly documented RFC test vector. For live system testing, use an air-gapped machine or your authenticator app directly.