OpenAI TTS Expressive AI Voice Generation

Expressive text-to-speech with custom voice instructions and 13 built-in voices.

OpenAI TTS is OpenAI's text-to-speech model powered by GPT-4o Mini, offering expressive voice generation with custom voice instructions. It features 13 built-in voices and instruction-based control over delivery style. On Oakgen, a 1-minute narration (up to 1,000 characters) costs about 6 credits (~$0.02).

1. 13 built-in voices with distinct characters
2. Instruction-based voice control ('speak slowly', 'whisper')
3. Natural pacing and emphasis from GPT backbone
4. 3–6 second latency per request
5. Strong for narration and dialogue

1. Choose a voice character

   Pick from 13 voices — Alloy, Echo, Fable, Onyx, Nova, Shimmer, and more. Each has a distinct personality.

2. Add voice instructions

   Use instructions to shape delivery — 'speak in a warm, conversational tone' or 'read this like a news anchor'.

curl -X POST https://api.oakgen.ai/v1/generate/speech \
  -H "Authorization: Bearer $OAKGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai-tts",
    "voice": "nova",
    "text": "Welcome to the future of AI-powered creativity."
  }'

vs. elevenlabs-v3 — ease of use

OpenAI TTS is simpler to use with built-in voices and instruction-based control. ElevenLabs v3 wins on voice cloning fidelity and emotional range.

Licensed through OpenAI's commercial terms.

Permitted on all paid Oakgen plans.