Skip to content
For the complete documentation index, see llms.txt. Markdown versions of documentation pages are available by appending .md to the page URL.
Primary navigation

Suggested
Overview Models Agents Tools Audio & voice Production API reference

Create speech

$ openai audio:speech create
POST/audio/speech

Generates audio from the input text.

Returns the audio file content, or a stream of audio events.

ParametersExpand Collapse
--input: string

The text to generate audio for. The maximum length is 4096 characters.

--model: string or SpeechModel

One of the available TTS models: tts-1, tts-1-hd, gpt-4o-mini-tts, or gpt-4o-mini-tts-2025-12-15.

--voice: string or "alloy" or "ash" or "ballad" or 10 more or object { id }

The voice to use when generating the audio. Supported built-in voices are alloy, ash, ballad, coral, echo, fable, onyx, nova, sage, shimmer, verse, marin, and cedar. You may also provide a custom voice object with an id, for example { "id": "voice_1234" }. Previews of the voices are available in the Text to speech guide. Custom voices must be created from audio samples.

--instructions: optional string

Control the voice of your generated audio with additional instructions. Does not work with tts-1 or tts-1-hd.

--response-format: optional "mp3" or "opus" or "aac" or 3 more

The format to audio in. Supported formats are mp3, opus, aac, flac, wav, and pcm.

--speed: optional number

The speed of the generated audio. Select a value from 0.25 to 4.0. 1.0 is the default.

--stream-format: optional "sse" or "audio"

The format to stream the audio in. Supported formats are sse and audio. sse is not supported for tts-1 or tts-1-hd.

ReturnsExpand Collapse
unnamed_schema_1: file path

Create speech

openai audio:speech create \
  --api-key 'My API Key' \
  --input input \
  --model tts-1 \
  --voice ash
Returns Examples