Amazon Cognito - Amazon Cognito lets you add user sign-up, sign-in, and access control to your web and mobile apps quickly and easily. It scales to millions of users and supports sign-in with social identity providers and enterprise identity providers via SAML 2.0.

Yoti Age Verification - This tool was built as a privacy-first approach to age verification that requires no other information aside from one's appearance.

NoPass.me - Open-source identity verification

Hulk Age Verification - Hulk Age Verification Popup lets you easily add a professional age gate or age verification popup banner on your website to verify visitors' age, ensure legal compliance, and avoid costly fines.

Authenteq - User-owned and controlled blockchain-based online ID

Yoti - A simple, secure way to store and prove your identity