API keys are crucial for secure communication between online services, but they can be vulnerable to attacks if not handled properly. Developers must prioritize robust API key security practices to prevent unauthorized access to their applications. This includes using environment variables, dedicated secret managers, backend proxies, and implementing regular key rotation. Additionally, best practices such as limiting permissions, monitoring usage, and rotating keys regularly are essential for maintaining a comprehensive security posture. By understanding common mistakes developers make while storing API keys and implementing secure storage methods, developers can protect their applications from potential security breaches.