# Novita AI Text-To-Speech API | Natural-Sounding Speech Synthesis

> Utilize the Novita AI Text-To-Speech API to convert written text into natural-sounding speech across multiple languages. Employing advanced voice synthesis technology, this API delivers clear and lifelike vocal output, ideal for e-learning platforms, accessibility tools, virtual assistants, and multimedia presentations. Authenticate your requests with API keys, manageable via the Novita AI Dashboard. Explore comprehensive API documentation and examples.

> For the complete documentation index, see [llms.txt](/llms.txt). Markdown is available with `Accept: text/markdown` and `.md` URL variants.

Source: /docs/api-reference/model-apis-txt2speech

# Text to Speech

POST

/

v3

/

async

/

txt2speech

Try it

Text to Speech

cURL

```
curl --request POST \
--url https://api.novita.ai/v3/async/txt2speech \
--header 'Authorization: ' \
--header 'Content-Type: ' \
--data '
{
"extra": {
"response_audio_type": "",
"webhook": {
"url": "",
"test_mode": {
"enabled": true,
"return_task_status": ""
}
},
"enterprise_plan": {
"enabled": true
}
},
"request": {
"voice_id": "",
"language": "",
"texts": [
""
],
"volume": 123,
"speed": 123
}
}
'
```

200

```
{
"task_id": ""
}
```

This Text-To-Speech API converts written text into natural-sounding speech across multiple languages. Utilizing advanced voice synthesis technology, it delivers clear and lifelike vocal output, suitable for a wide range of applications, including e-learning platforms, accessibility tools, virtual assistants, and multimedia presentations.

This is an asynchronous API; only the task_id will be returned. You should use the task_id to request the [Task Result API](/docs/api-reference/model-apis-task-result) to retrieve the speech generation results.

##

[​](#request-headers)

Request Headers

[​](#param-content-type)

Content-Type

string

required

Enum: `application/json`

[​](#param-authorization)

Authorization

string

required

Bearer authentication format, for example: Bearer {{API Key}}.

##

[​](#request-body)

Request Body

[​](#param-extra)

extra

object

Optional extra parameters for the request.

Show properties

[​](#param-response-audio-type)

response_audio_type

string

The returned audio type. Default is wav.

Enum: `wav`, `mp3`

[​](#param-webhook)

webhook

object

Webhook settings. More details can be found at [Webhook Documentation](/docs/api-reference/model-apis-webhook).

Show properties

[​](#param-url)

url

string

required

The URL of the webhook endpoint. Novita AI will send the task generated outputs to your specified webhook endpoint.

[​](#param-test-mode)

test_mode

object

By specifying Test Mode, a mock event will be sent to the webhook endpoint.

Show properties

[​](#param-enabled)

enabled

boolean

required

Set to true to enable Test Mode, or false to disable it. The default is false.

[​](#param-return-task-status)

return_task_status

string

required

Control the data content of the mock event. When set to TASK_STATUS_SUCCEED, you’ll receive a normal response; when set to TASK_STATUS_FAILED, you’ll receive an error response.

Enum: `TASK_STATUS_SUCCEED`, `TASK_STATUS_FAILED`

[​](#param-enterprise-plan)

enterprise_plan

object

Dedicated Endpoints settings, which only take effect for users who have already subscribed to the [Dedicated Endpoints Documentation](/docs/guides/model-apis-dedicated-endpoints).

Show properties

[​](#param-enabled-1)

enabled

boolean

Set to true to schedule this task to use your Dedicated Endpoints’s dedicated resources. Default is false.

[​](#param-request)

request

object

required

Hide properties

[​](#param-voice-id)

voice_id

string

required

Voice ID

Enum: `Emily`, `James`, `Olivia`, `Michael`, `Sarah`, `John`

[​](#param-language)

language

string

required

Identify the languages spoken in the generated audio

Enum: `en-US`, `zh-CN`, `ja-JP`

[​](#param-texts)

texts

string[]

required

Source text for synthetic speech, UTF-8 encoded, supporting a maximum of 512 characters.

[​](#param-volume)

volume

number

Control the volume of the generated audio; select a value between 1.0 and 2.0. The default value is 1.0.

[​](#param-speed)

speed

number

Control the speed of the generated audio; select a value between 0.8 and 3.0. The default value is 1.0.

##

[​](#response)

Response

[​](#param-task-id)

task_id

string

Use the task_id to request the [Task Result API](/docs/api-reference/model-apis-task-result) to retrieve the generated outputs.

##

[​](#example)

Example

request

```
curl --location 'https://api.novita.ai/v3/async/txt2speech' \
--header 'Authorization: Bearer {{API Key}}' \
--header 'Content-Type: application/json' \
--data '{
"request": {
"voice_id": "Emily",
"language": "en-US",
"texts": [
"To be or not to be, that is a question."
],
"volume": 1.2,
"speed": 1.0
}
}'
```

response

```
{
"task_id": "b49df8dc-4a72-474b-a863-xxx"
}
```

Last modified on January 14, 2026