Numbers

OTP Code Generator

An OTP (One-Time Passcode) generator creates the kind of short numeric codes used in two-factor authentication (2FA), SMS verification, email verification flows, and app login systems. This tool is invaluable for developers building and testing authentication systems who need realistic OTP codes without triggering a real SMS or email service. Generate 4, 6, or 8-digit codes in bulk with optional grouping separators to match your UI design. All codes are generated client-side with no external calls.

Use Cases

  • •Testing 2FA authentication flows
  • •Prototyping SMS verification UIs
  • •Generating mock email verification codes
  • •Load testing authentication endpoints
  • •Demoing login screen designs

FAQ

What is an OTP code?

A One-Time Passcode is a short numeric code, usually 4–8 digits, that is valid for a single login attempt or a short time window.

How many digits should an OTP be?

6 digits is the most common standard, used by Google Authenticator, Authy, and most SMS verification systems.

Can I use these codes for real authentication?

These are randomly generated mock codes for testing — they are not tied to any TOTP algorithm or time-based secret.

Why do some OTPs have a dash in the middle?

A separator like a dash improves readability, making it easier for users to read and type the code correctly.