ElevenLabs and Play.ai are two prominent conversational AI platforms designed to create customizable voice agents. Both platforms feature in-house text-to-speech (TTS) capabilities, with ElevenLabs additionally offering in-house speech-to-text (STT) models to enhance latency and control, while Play.ai integrates with external providers for realistic voices. Supporting multiple languages, ElevenLabs covers over 70 languages, whereas Play.ai supports over 30. The platforms provide tools for API calls, knowledge base management, and telephony integrations and cater to different user needs based on requirements such as voice customization, data retention policies, and multilingual support. ElevenLabs excels with its vast voice library and enterprise-level features, whereas Play.ai focuses on realistic voice generation and broader conversational AI tools. The choice between the two depends on specific needs, such as real-time analytics, security, and customization.