GPT-4o mini TTS

Technical Specifications of gpt-4o-mini-tts

gpt-4o-mini-tts is a text-to-speech model exposed through the audio speech API for generating natural-sounding spoken audio from text. It is positioned for intelligent realtime applications and supports prompt-based control over speech characteristics such as accent, emotional range, intonation, impressions, speed of speech, tone, and whispering.

From the API perspective, gpt-4o-mini-tts is used with the speech generation endpoint and accepts core inputs including the model ID, input text, and a selected voice. The input text limit is 4096 characters per request. Supported built-in voices include alloy, ash, ballad, coral, echo, fable, onyx, nova, sage, shimmer, verse, marin, and cedar, with support for custom voice objects where available.

The model supports multiple output formats for generated audio, including mp3, opus, aac, flac, wav, and pcm. It also supports a configurable speech speed from 0.25 to 4.0, with 1.0 as the default. For delivery behavior, the API supports direct audio output as well as streaming options, including SSE streaming for responsive playback workflows.

Typical implementation scenarios include voice assistants, IVR and contact flows, product read-aloud experiences, accessibility narration, and media voice generation where low latency and natural voice output matter. This fits the model’s documented positioning for realtime audio generation.

What is gpt-4o-mini-tts?

gpt-4o-mini-tts is a neural text-to-speech model that converts written text into expressive, natural audio for user-facing applications. It is designed for teams that need fast voice generation without building and training a custom speech stack from scratch.

In practical terms, developers send text plus a chosen voice to the speech API, and the model returns synthesized audio that can be saved, streamed, or played back in an application. Because it supports multiple voices, common audio export formats, and streaming-friendly delivery, it is well suited to production interfaces that need spoken responses with minimal delay.

Compared with basic TTS pipelines, gpt-4o-mini-tts is especially useful when the experience needs more than robotic narration. The documented controls over tone, pacing, accent, and expressive style make it a strong option for assistants, guided workflows, customer service automation, and branded voice experiences.

Main features of gpt-4o-mini-tts

• Natural speech generation: Converts text into human-like spoken audio intended for user-facing and realtime experiences.
• Low-latency delivery: Designed for intelligent realtime applications, making it suitable for conversational interfaces and responsive playback flows.
• Selectable voices: Supports a range of built-in voices such as alloy, ash, ballad, coral, echo, fable, onyx, nova, sage, shimmer, verse, marin, and cedar.
• Expressive control: Can be prompted to shape accent, emotional range, intonation, impressions, tone, whispering, and speed of speech.
• Multiple audio formats: Exports generated speech in mp3, opus, aac, flac, wav, and pcm formats for different application and playback needs.
• Streaming synthesis support: Supports streaming-oriented response behavior, including SSE, for applications that need progressive audio delivery.
• Simple API integration: Works through a straightforward speech generation API using model, input text, and voice parameters.
• Custom voice pathway: Can be paired with custom voice objects where account eligibility and voice-creation workflows are available.

How to access and integrate gpt-4o-mini-tts

Step 1: Sign Up for API Key

To start using gpt-4o-mini-tts, first create an account on CometAPI and generate your API key from the dashboard. After signing in, copy the key and store it securely, since you will use it to authenticate every request to the API.

Step 2: Send Requests to gpt-4o-mini-tts API

Once you have your API key, you can call CometAPI’s OpenAI-compatible endpoint and specify the model as gpt-4o-mini-tts.

curl https://api.cometapi.com/v1/audio/speech \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $COMETAPI_API_KEY" \
  -d '{
    "model": "gpt-4o-mini-tts",
    "input": "Welcome to our voice assistant. How can I help you today?",
    "voice": "alloy",
    "response_format": "mp3"
  }' \
  --output speech.mp3

import requests

url = "https://api.cometapi.com/v1/audio/speech"
headers = {
    "Authorization": "Bearer YOUR_COMETAPI_API_KEY",
    "Content-Type": "application/json",
}
payload = {
    "model": "gpt-4o-mini-tts",
    "input": "Welcome to our voice assistant. How can I help you today?",
    "voice": "alloy",
    "response_format": "mp3",
}

response = requests.post(url, headers=headers, json=payload)
with open("speech.mp3", "wb") as f:
    f.write(response.content)

Step 3: Retrieve and Verify Results

After sending the request, CometAPI returns the generated audio output for gpt-4o-mini-tts. Save the returned file or stream it directly into your application, then verify that the selected voice, format, pacing, and overall audio quality match your product requirements. If needed, adjust the input text, voice choice, output format, or speech settings and resend the request until the result fits your use case.