OpenAI TTS Voices

Listen to all 9 voices. Pick a sample text, choose your model and speed, then hit play.

Sample
Model
Speed

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TTS-1 vs TTS-1-HD: Which model should you use?

Compare quality, latency, and cost between OpenAI's two text-to-speech models.

Frequently Asked Questions

What is OpenAI TTS?

OpenAI's text-to-speech API converts written text into natural-sounding audio. It offers 9 built-in voices and two model variants: tts-1 for low-latency applications and tts-1-hd for higher fidelity output.

What voices are available?

OpenAI TTS includes 9 voices: Alloy (neutral), Ash (warm), Coral (clear), Echo (deep), Fable (animated), Nova (bright), Onyx (bold), Sage (calm), and Shimmer (soft). Each has a distinct character suited for different use cases.

What's the difference between tts-1 and tts-1-hd?

The tts-1 model is optimized for speed and low latency, ideal for real-time applications. tts-1-hd produces higher quality audio with better clarity, best for pre-rendered content.

How does speed control work?

Playback speed can be set from 0.25x to 4.0x when generating audio. Lower speeds sound more deliberate, while higher speeds are useful for faster narration. The speed is baked into the generated audio file.

What audio formats does OpenAI TTS support?

The API supports MP3, WAV, OPUS, AAC, FLAC, and PCM output formats. MP3 is the default and most widely compatible. All samples on TextToLab use MP3.

How much does OpenAI TTS cost?

OpenAI charges $15 per 1 million characters for tts-1 and $30 per 1 million characters for tts-1-hd. A typical 1,000-word blog post costs about $0.08 to $0.16.

Which voice should I use?

It depends on your content. Alloy works for most general use cases. Echo and Onyx suit narration and announcements. Nova and Ash are friendly for apps and chatbots. Sage and Shimmer work well for calm, instructional content.

What is TextToLab?

TextToLab is a free tool for previewing and comparing AI text-to-speech voices. All audio samples are pre-generated so you can quickly evaluate voices without needing an API key or spending credits.