What OpenAI TTS HD does
OpenAI TTS HD is the text-to-speech endpoint of the OpenAI Audio API, which turns text into spoken audio for developers. Models are gpt-4o-mini-tts, recommended for realtime use, tts-1 for lower latency, and tts-1-hd for higher quality. The API offers 13 built-in voices, optimized for English, and supports about 60 languages. Output formats include MP3, Opus, AAC, FLAC, WAV, and PCM, with streaming through chunked transfer encoding. Usage policies require disclosure that the voice is AI-generated, and the page does not state pricing. It is documented alongside the Realtime API and the OpenAI SDKs and CLI.
How OpenAI TTS HD compares with its closest alternatives
4 of the 5 closest alternatives have a free plan; OpenAI TTS HD does not. 4 of the 5 offer an API, as OpenAI TTS HD does. OpenAI TTS HD was founded in 2022; the alternatives were founded between 2020 and 2023, 1 of them earlier. OpenAI TTS HD is based in San Francisco, United States; 1 of the 4 alternatives with a known headquarters is in the United States too, and the others in the United Kingdom.