Top Castle Alternatives

Clerk

Clerk is an authentication and user management platform for web apps, providing tools for secure login, session management, and user data handling.

UAE PASS

UAE PASS is a national digital identity app for accessing online services, signing documents, and managing official records securely in the UAE.

Auth Armor

Auth Armor is a secure authentication platform using biometrics for easy, passwordless login and enhanced user identity management across applications.

Auth0

Auth0 is an identity and access management platform that simplifies user authentication and authorization for various applications.

Authsignal

Authsignal is an authentication platform offering passkeys and passwordless solutions for secure customer identity verification and fraud mitigation.

Privy

The Privy app provides secure digital signatures and digital ID solutions for businesses in Indonesia, enabling legal online transactions and identity verification.

Dynamic

Dynamic is a multi-chain wallet authentication and authorization platform that provides a user-friendly login experience.

ID.me

ID.me is a digital identity verification app that securely authenticates users' identities for various services, preventing fraud and ensuring compliance with standards.

Passage by 1Password

Passage by 1Password enables passwordless sign-in using passkeys for apps and websites, simplifying authentication integration and enhancing security.

Okta

Okta is an identity management platform that secures user access to applications and resources through single sign-on and multi-factor authentication.

Cloudflare Zero Trust

Cloudflare Zero Trust enforces access controls using a Zero Trust model, integrating with identity providers to secure application access and network traffic.

Yoti

Yoti is a digital identity app that securely stores personal information and facilitates age verification using biometrics and document checks.

Persona

Persona is an identity management platform that automates user information verification and fraud detection for businesses.

LoginID

LoginID is an authentication platform that provides passwordless, biometric solutions for secure login across various industries, enhancing user experience and security.

Microsoft Entra Admin Center

Microsoft Entra Admin Center manages identities and access across environments, offering features like user management, role-based access, and conditional access.

Stytch

Stytch is an identity platform providing secure, passwordless authentication solutions for developers, including SDKs for easy integration in web and mobile apps.

Google Admin

Google Admin allows administrators to manage users, groups, and security settings for Google services, as well as handle licenses and domain configurations.

SimpleLogin

SimpleLogin allows users to create unique email aliases for each website, helping protect their original email addresses from phishing and spam.

Azure Active Directory

Azure Active Directory is a cloud-based identity service that provides single sign-on, multi-factor authentication, and access management for users and applications.

WhatsAuth

WhatAuth is a secure OTP solution using WhatsApp for authentication tasks like login, password recovery, and transaction verification, offering a cost-effective alternative to SMS.

GPT Auth

The GPT Auth app allows users to customize their GPTs with no-code actions, enabling connections to any API for data management.

PureAUTH

PureAUTH is an identity and access platform using certificate-based PKI and zero-trust controls to verify users and machines, manage trust, and secure infrastructure access.

Duo Admin

Duo Admin is a management tool that helps organizations enforce access policies, manage user authentication, and ensure device security for application access.

SuperTokens

SuperTokens is an open-source user authentication solution that simplifies secure login processes for web and mobile applications.

Youverse

Youverse allows users to manage accounts and authenticate identity using facial recognition without disclosing biometrics or requiring passwords.

IPQS

IPQS provides an API suite for detecting and preventing fraud, including bots and fake data, by validating digital identities in real-time.

AuthSmith

AuthSmith provides authentication and access control for apps: email/password, social sign‑in, SSO, MFA, role-based access, activity analytics, alerts, API integrations, and encrypted user data.

Tesseral

Tesseral is an open-source platform for managing authentication and authorization in B2B software, allowing developers to handle user identities securely and efficiently.

CyberArk

CyberArk secures identities and manages access to sensitive systems, protecting organizations from cyber threats through privileged access management and automated security tools.

JumpCloud

JumpCloud is a cloud-based identity management platform that securely manages user identities, devices, and access across various resources.