To detect browser support for WebAuthn, developers can check if the `PublicKeyCredential` object is available in JavaScript. Currently, 87.39% of internet users should have support, with platform authenticators being the main method of adoption due to their lower cost and wider availability compared to roaming authenticators. To determine if a platform authenticator is supported, developers can use the `isUserVerifyingPlatformAuthenticatorAvailable()` method. WebAuthn is an API that reduces reliance on passwords by using public key cryptography to create credentials for websites, making it less vulnerable to phishing attacks. Developers who want to learn more about WebAuthn and its implementation can check out resources such as https://webauthn.guide/ or Twilio's Verify API for a wide range of authentication channels.