A serverless progressive web application that generates TOTP and HOTP codes, enabling robust two-factor authentication (2FA) directly within your browser. Powered by Nuxt 4, NuxtHub, NuxtUI 3, Cloudflare Pages, D1 Database, and Drizzle ORM.

HOTP/TOTP one time passwords on java phones (J2ME)

HMAC Based One Time Passwords in PHP. RFC4226 and RFC6238 compliant.

Nextcloud app that allows you to manage your OTP (TOTP/HOTP) codes easily

Nextcloud app that allows you to manage your OTP (TOTP/HOTP) codes easily

HOTP and TOTP algorithms in Erlang.

Online One Time Password (HOTP/TOTP) generator.

Similar to the Google authenticator just written in Python to automate annoying two factor authentication.

Go library for one-time passwords, supports HOPT and TOPT (Google Authenticator compatible)

Cross-platform console C#/.Net implementation to generate one time passwords (TOTP/HOTP) for open authentication defined by standard RFC's (4226, 6238). Compatible with Google/Microsoft Authenticator apps.

Minimal Free Pascal implementation of TOTP and HOTP algorithms using SHA1 and SHA256. Supports both time-based and counter-based OTP generation.

A simple, easy-to-use one-time password generator implementation for .NET Core 3.1. Compatible with Google Authenticator.

OTPLib Delphi Library

A Swift library that provides cryptographic authentication algorithms like OCRA, HOTP etc.

Kotlin Multiplatform library for OTP and TOTP password generation/validation

Implementation of HOTP and TOTP as per the RFC RFC4226 and RFC6238 respectively

HMAC-based one-time password generator. https://www.nuget.org/packages/sim756.HOTP

Authenticator app with Python.

Simple, dependency-free Go library for HOTP/TOTP (RFC 4226/6238) — generate, verify, and integrate OTPs for 2FA.

Lightweight TypeScript HOTP/TOTP library