What is OTP and how does TOTP work?

OTP (One-Time Password) is a temporary password that's valid for only one login session or transaction. Unlike regular passwords that remain the same until you change them, OTPs expire after a short period or single use, making them much more secure against hackers and unauthorized access.

TOTP (Time-based One-Time Password) is the most common type of OTP used in two-factor authentication (2FA). It works by combining a secret key (shared between you and the service) with the current time to generate a unique 6-digit code. This code changes automatically every 30 seconds. Both your authenticator app and the service use the same algorithm and secret key, so they generate matching codes at the same time. When you enter the code during login, the service verifies it matches what it generated, confirming you have access to the secret key stored in your authenticator app.

This method is widely used to protect accounts on Google, Microsoft, GitHub, banking apps, and thousands of other services. Even if someone steals your password, they can't access your account without the constantly changing TOTP code from your authenticator device.

Tool description

An instant OTP generator and comprehensive tool for generating and managing time-based one-time passwords (TOTP) for two-factor authentication (2FA). This OTP code generator online allows you to generate secure OTP tokens instantly, view QR codes for easy setup in authenticator apps, and monitor token expiration with a real-time countdown timer.

Features

  • OTP Secret Key Generator: Generate random secret keys instantly or input your own custom secret for OTP generation
  • Instant 6-Digit Token Generation: Automatically generates time-based 6-digit authentication codes as an instant OTP generator
  • QR Code Display: Visual QR code for quick setup in authenticator apps like Google Authenticator, Authy, or Microsoft Authenticator
  • URI Export: Copy the OTP URI for manual entry or integration with authentication systems
  • Real-Time Countdown: Live progress bar showing remaining time before token expires
  • 30-Second Refresh: Automatic token regeneration every 30 seconds following TOTP standards
  • One-Click Copy: Easily copy secret, token, or URI to clipboard
  • Secure Generation: Uses industry-standard TOTP algorithm (RFC 6238) via otplib library

Use Cases

  • Setting Up 2FA: Use this OTP code generator online to create QR codes and set up two-factor authentication on your accounts instantly
  • Testing Authentication: Validate your 2FA implementation by generating test tokens with our instant OTP generator
  • Security Auditing: Verify TOTP token generation and synchronization in your applications
  • Secret Key Generation: Use the OTP secret key generator to create secure keys for backup access to accounts that support TOTP authentication
  • Development: Test two-factor authentication flows during application development with instant code generation
  • Account Recovery: Use your secret key with this OTP code generator online to regain access to authenticator apps on new devices
  • Integration Testing: Verify TOTP integration with authentication services and APIs using our instant OTP generator