Add TOTP Two-Factor to Your Own App: A Developer Guide
A framework-agnostic guide to adding RFC 6238 TOTP two-factor auth: generate a secret, build the otpauth URI, verify codes with a drift window, and stop replay.
Read more →All articles about authenticator: 3 practical guides and tutorials from our free, privacy-first online tools.
A framework-agnostic guide to adding RFC 6238 TOTP two-factor auth: generate a secret, build the otpauth URI, verify codes with a drift window, and stop replay.
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Dissect the otpauth:// Key URI a 2FA QR code carries: scheme, totp host, issuer:account label, and the secret, algorithm, digits, and period parameters.
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Your TOTP code rejected? The fixes ordered by likelihood: clock skew first, then wrong algorithm, digits, period, mistyped secret, and reused codes.
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