OpenAI.fm

OpenAI.fm serves as an interactive demo platform by OpenAI for developers to test their latest text-to-speech (TTS) model in the API, enabling real-time conversion of text to natural, customizable AI-generated speech.​

Key Features

Users select from preset voices like Alloy, Ash, Ballad, Coral, Echo, Fable, Nova, Sage, Shimmer, and Verse, with steerable styles such as dramatic, sports coach, mad scientist, or auctioneer for expressive outputs. It supports multilingual audio, emotional tone adjustments, flexible text/file inputs, zero data retention for privacy, and API integration for apps. Output formats include MP3 and WAV for low-latency streaming in voice agents.​

Launch and Models

Launched around March 20, 2025, alongside new API audio models including gpt-4o-mini-tts for steerable TTS, plus gpt-4o-transcribe and gpt-4o-mini-transcribe for improved speech-to-text accuracy over Whisper. These models use advanced pretraining on audio datasets, distillation, and reinforcement learning for better handling of accents, noise, and speed variations. The demo powers prototyping for voice agents, content creation, and customer service bots, with GitHub code available at openai/openai-fm.​​

Use Cases

Due to its free access, developer focus, and recent 2025 updates like Realtime API integration for production voice apps—no major changes reported post-March beyond API expansions. Developers praise its life-like, promptable emotions (e.g., “sympathetic customer service agent”) for YouTube voiceovers, podcasts, or SEO-optimized financial content narration. List it under TTS categories with tags for OpenAI API, real-time audio, and steerability to attract web devs and creators.