Credential stuffing attacks continue to threaten businesses by using stolen credentials to automate unauthorized login attempts. This guide covers the best practices for preventing credential stuffing and blocking bot attacks, including multi-factor authentication (MFA), passkeys, bot detection, rate limiting, CAPTCHA, device fingerprinting, and adaptive authentication. Learn how to protect user accounts, reduce account takeover risks, and strengthen your authentication strategy while maintaining a secure, seamless login experience for legitimate users across web and mobile applications.