--- title: "2FA Code Tester" description: "Test and verify TOTP (Time-based One-Time Password) codes from authenticator apps. Debug 2FA setup issues and verify your authentication is working correctly." url: https://findutils.com/security/two-fa-code-tester/ category: security --- # 2FA Code Tester Test and verify TOTP (Time-based One-Time Password) codes from authenticator apps. Debug 2FA setup issues and verify your authentication is working correctly. **Use this tool:** [2FA Code Tester](https://findutils.com/security/two-fa-code-tester/) ## Programmatic access - REST id `two-fa-code-tester`: POST https://api.findutils.com/api/tools/two-fa-code-tester/execute (reference: https://findutils.com/api/two-fa-code-tester/) - MCP tool `two_fa_code_tester` on https://mcp.findutils.com (reference: https://findutils.com/mcp/two-fa-code-tester/) ## Why Test 2FA Codes? Two-factor authentication adds crucial security to your accounts. This tool helps debug setup issues, verify time synchronization, and test TOTP implementations. ## Tips for Reliable 2FA - Always keep your device clock set to automatic network time. Even a 30-second drift can cause TOTP codes to fail. - Store backup codes in a secure location such as an encrypted password manager. If you lose access to your authenticator app, backup codes are your only recovery path. - When setting up 2FA, save the secret key or QR code before activating it. This allows you to re-add the account to a new device without contacting support. - Use a TOTP app that supports encrypted cloud backup (like Authy or 1Password) so you do not lose all your tokens if your phone is lost or damaged. - Test your 2FA codes immediately after setup. Do not close the setup page until you have confirmed the code from your authenticator matches and is accepted. ## Frequently Asked Questions ### What is TOTP? Time-based One-Time Password (TOTP) generates temporary codes that change every 30 seconds, based on a shared secret and current time. It is defined in RFC 6238 and is the standard behind most authenticator apps including Google Authenticator, Authy, and Microsoft Authenticator. ### Why might my codes not work? Common issues include incorrect time on your device, wrong secret key, or the account being set up with a different algorithm. Ensure your device time is synced to network time. Even a 30-second offset can cause every code to be rejected. ### Is it safe to enter my secret here? All processing happens locally in your browser. Your secret key is never sent to any server. The TOTP computation runs entirely in client-side JavaScript, so your secret remains private even on shared networks. ### What apps work with TOTP? Google Authenticator, Microsoft Authenticator, Authy, 1Password, Bitwarden, and many other apps support TOTP. Any app compliant with RFC 6238 will work. Hardware tokens like YubiKey also support TOTP. ### What is a base32 secret key? A base32 secret key is the shared secret encoded using the base32 alphabet (A-Z and 2-7). It is the format used by virtually all TOTP providers. You receive this key during 2FA setup, either as a text string or embedded in a QR code. ### Can I use this tool to set up 2FA on my accounts? This tool is designed for testing and debugging, not for setting up 2FA. To enable two-factor authentication, use a dedicated authenticator app like Google Authenticator or Authy and follow the setup instructions provided by each service. ### Why does my code expire so quickly? TOTP codes are designed to be short-lived for security. Each code is valid for a 30-second window. This time limit ensures that even if a code is intercepted, the attacker has only seconds to use it before it becomes invalid. ### What happens if I lose my authenticator device? If you lose your device, you will need backup codes (provided during setup) or must contact each service's support team to regain access. This is why storing backup codes securely is critical. Some authenticator apps like Authy offer encrypted cloud backup to prevent this scenario. ### Does this tool support different TOTP configurations? The tool supports the standard TOTP configuration: SHA-1 algorithm, 6-digit codes, and 30-second time steps. These are the defaults used by the vast majority of services. Some services use SHA-256 or 8-digit codes, which are less common. ### How is TOTP different from SMS-based 2FA? TOTP codes are generated locally on your device using a cryptographic algorithm, making them immune to SIM-swapping attacks and phone number hijacking. SMS-based 2FA sends codes over the cellular network, which can be intercepted. Security experts strongly recommend TOTP over SMS wherever possible. ## Related Tools - [Password Generator](https://findutils.com/security/password-generator/) - [Password Strength Checker](https://findutils.com/security/password-strength-checker/) - [Random Key Generator](https://findutils.com/security/random-key-generator/) - [JWT Decoder](https://findutils.com/developers/jwt-decoder/) - [HMAC Generator](https://findutils.com/security/hmac-generator/) - [Hash Comparison Tool](https://findutils.com/security/hash-comparison-tool/) - [Password Breach Checker](https://findutils.com/security/password-breach-checker/) - [Text Encryption](https://findutils.com/security/text-encryption/)