---
title: "Generates audio from the input text."
method: POST
path: "/audio/speech"
tags: ["Audio"]
---

# Generates audio from the input text.

`POST /audio/speech`

## Request body

- CreateSpeechRequest
  - `model` union, required — One of the available [TTS models](/docs/models#tts): `tts-1`, `tts-1-hd` or `gpt-4o-mini-tts`.
    - string
    - 'tts-1' | 'tts-1-hd' | 'gpt-4o-mini-tts'
  - `input` string, required — The text to generate audio for. The maximum length is 4096 characters.
  - `instructions` string — Control the voice of your generated audio with additional instructions. Does not work with `tts-1` or `tts-1-hd`.
  - `voice` union, required
    - string
    - 'alloy' | 'ash' | 'ballad' | 'coral' | 'echo' | 'fable' | 'onyx' | 'nova' | 'sage' | 'shimmer' | 'verse'
  - `response_format` 'mp3' | 'opus' | 'aac' | 'flac' | 'wav' | 'pcm' — The format to audio in. Supported formats are `mp3`, `opus`, `aac`, `flac`, `wav`, and `pcm`.
  - `speed` number — The speed of the generated audio. Select a value from `0.25` to `4.0`. `1.0` is the default.

## Response `200`

OK

## Changes

- **2025-03-22** `41844462b873` — 10 breaking, 3 info
  - removed the enum value `alloy` of the request property `voice`
  - removed the enum value `ash` of the request property `voice`
  - removed the enum value `coral` of the request property `voice`
  - removed the enum value `echo` of the request property `voice`
  - …9 more
- **2025-01-21** `47138a7dd8b9` — 3 info
  - added the new `ash` enum value to the request property `voice`
  - added the new `coral` enum value to the request property `voice`
  - added the new `sage` enum value to the request property `voice`
- **2025-01-21** `0d83ef8a5f65` — 3 breaking
  - removed the enum value `ash` of the request property `voice`
  - removed the enum value `coral` of the request property `voice`
  - removed the enum value `sage` of the request property `voice`
- **2025-01-17** `88f3bede7665` — 3 info
  - added the new `ash` enum value to the request property `voice`
  - added the new `coral` enum value to the request property `voice`
  - added the new `sage` enum value to the request property `voice`
- …earlier changes not shown

[Full history](https://skmtc.dev/openai/apis/openapi/changes/audio/speech/post.md)

---

[API](https://skmtc.dev/openai/apis/openapi.md) · [All operations](https://skmtc.dev/openai/apis/openapi/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/openai/openapi/revisions/6a6c681b1820/schema)