TOTP code verifier
Confirm that a one-time password matches a Base32 secret. Useful when a login keeps rejecting codes.
Verifier FAQ
Why would a valid-looking code fail?
Clock drift, the wrong secret, or a different period/algorithm than the issuer used. This verifier allows ±1 time step (30 seconds either side) by default.
Does verification send my secret to a server?
No. The check runs in your browser with the same RFC 6238 math as the generator.
Related 2FA tools
TOTP generator
Live 6-digit 2FA codes from a Base32 secret, with optional device-saved accounts.
Base32 encoder
Encode or decode RFC 4648 Base32 used by authenticator apps.
Secret generator
Create a random Base32 TOTP secret for new 2FA enrollments.
otpauth URI builder
Build a standard otpauth://totp URI for authenticator apps.
Online authenticator
How an online TOTP tool compares with Google Authenticator.