Prompt injection attacks pose a significant threat to various applications, and the lack of a unified evaluation platform hinders the comparison of defense mechanisms. To address this gap, researchers have introduced PIArena, a platform designed to assess the robustness of prompt injection defenses. This platform enables the evaluation of defenses against diverse attacks and tasks, providing a comprehensive understanding of their effectiveness. By utilizing PIArena, developers can reliably compare and assess the true robustness of their defenses, ultimately enhancing the security of their applications. The development of PIArena is a crucial step in mitigating the risks associated with prompt injection attacks, which can have severe consequences in real-world applications1. So what matters to practitioners is that PIArena can help them develop more robust defenses against prompt injection attacks, thereby protecting their applications from potential security breaches.