---
title: Inworld TTS 1.5 Mini
description: Ultra-fast, cost-efficient text-to-speech with approximately 120ms latency and 15-language support.
image: https://developers.cloudflare.com/dev-products-preview.png
---

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![Inworld logo](https://developers.cloudflare.com/_astro/inworld.BDwMAXI2.svg) 

#  Inworld TTS 1.5 Mini 

Text-to-Speech • Inworld 

`inworld/tts-1.5-mini` 

Ultra-fast, cost-efficient text-to-speech with approximately 120ms latency and 15-language support.

| Model Info          |                                                                                                                        |
| ------------------- | ---------------------------------------------------------------------------------------------------------------------- |
| Terms and License   | [link ↗](https://inworld.ai/terms)                                                                                     |
| More information    | [link ↗](https://inworld.ai/)                                                                                          |
| Zero data retention | Yes                                                                                                                    |
| Pricing             | [View pricing in the Cloudflare dashboard ↗](https://dash.cloudflare.com/?to=/:account/ai/models/inworld/tts-1.5-mini) |

## Usage

* [ TypeScript ](#tab-panel-808)
* [ cURL ](#tab-panel-809)

TypeScript

```
const response = await env.AI.run(  'inworld/tts-1.5-mini',  {    output_format: 'mp3',    temperature: 1,    text: 'Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.',    timestamp_type: 'none',    voice_id: 'Dennis',  },)console.log(response)
```

Terminal window

```
curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \  --header "Content-Type: application/json" \  --data '{  "model": "inworld/tts-1.5-mini",  "input": {    "output_format": "mp3",    "temperature": 1,    "text": "Hello! Welcome to Cloudflare AI Gateway. Let me show you what we can do.",    "timestamp_type": "none",    "voice_id": "Dennis"  }}'
```

* [ Output ](#tab-panel-804)
* [ Raw response ](#tab-panel-805)

```
{  "gatewayMetadata": {    "keySource": "Unified"  },  "result": {    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-mini/simple-speech.mp3"  },  "state": "Completed"}
```

## Examples

**Fast Speech**  — Speed up speech for quick playback 

* [ TypeScript ](#tab-panel-812)
* [ cURL ](#tab-panel-813)

TypeScript

```
const response = await env.AI.run(  'inworld/tts-1.5-mini',  {    output_format: 'mp3',    speaking_rate: 1.4,    temperature: 1,    text: 'This is a fast-paced summary of the key findings from the quarterly report. Revenue is up fifteen percent and user growth exceeded expectations.',    timestamp_type: 'none',    voice_id: 'Dennis',  },)console.log(response)
```

Terminal window

```
curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \  --header "Content-Type: application/json" \  --data '{  "model": "inworld/tts-1.5-mini",  "input": {    "output_format": "mp3",    "speaking_rate": 1.4,    "temperature": 1,    "text": "This is a fast-paced summary of the key findings from the quarterly report. Revenue is up fifteen percent and user growth exceeded expectations.",    "timestamp_type": "none",    "voice_id": "Dennis"  }}'
```

* [ Output ](#tab-panel-806)
* [ Raw response ](#tab-panel-807)

```
{  "gatewayMetadata": {    "keySource": "Unified"  },  "result": {    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-mini/fast-speech.mp3"  },  "state": "Completed"}
```

**Low Latency**  — Minimize latency by disabling text normalization 

* [ TypeScript ](#tab-panel-814)
* [ cURL ](#tab-panel-815)

TypeScript

```
const response = await env.AI.run(  'inworld/tts-1.5-mini',  {    apply_text_normalization: false,    output_format: 'mp3',    temperature: 1,    text: 'Quick response needed. The server is ready.',    timestamp_type: 'none',    voice_id: 'Dennis',  },)console.log(response)
```

Terminal window

```
curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run \  --header "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \  --header "Content-Type: application/json" \  --data '{  "model": "inworld/tts-1.5-mini",  "input": {    "apply_text_normalization": false,    "output_format": "mp3",    "temperature": 1,    "text": "Quick response needed. The server is ready.",    "timestamp_type": "none",    "voice_id": "Dennis"  }}'
```

* [ Output ](#tab-panel-810)
* [ Raw response ](#tab-panel-811)

```
{  "gatewayMetadata": {    "keySource": "Unified"  },  "result": {    "audio": "https://pub-04a6d208d361438ea01b797e6973bd19.r2.dev/catalog/inworld__tts-1.5-mini/low-latency.mp3"  },  "state": "Completed"}
```

## Parameters

* [ Input ](#tab-panel-816)
* [ Output ](#tab-panel-817)

text

`string`requiredmaxLength: 2000The text to be synthesized into speech. Maximum input of 2,000 characters.

voice\_id

`string`requireddefault: Dennisenum: Loretta, Darlene, Marlene, Hank, Evelyn, Celeste, Pippa, Tessa, Liam, Callum, Hamish, Abby, Graham, Rupert, Mortimer, Snik, Anjali, Saanvi, Arjun, Claire, Oliver, Simon, Elliot, James, Serena, Gareth, Vinny, Lauren, Jessica, Ethan, Tyler, Jason, Chloe, Veronica, Victoria, Miranda, Sebastian, Victor, Malcolm, Nate, Brian, Amina, Kelsey, Derek, Evan, Kayla, Jake, Grant, Tristan, Nadia, Selene, Marcus, Riley, Damon, Cedric, Mia, Naomi, Jonah, Levi, Avery, Brandon, Conrad, Bianca, Lucian, Trevor, Alex, Ashley, Craig, Deborah, Dennis, Edward, Elizabeth, Hades, Julia, Pixie, Mark, Olivia, Priya, Ronald, Sarah, Shaun, Theodore, Timothy, Wendy, Dominus, Hana, Clive, Carter, Blake, Luna, Reed, Duncan, Felix, Eleanor, SophieThe ID of the voice to use for synthesizing speech. Defaults to Dennis.

output\_format

`string`requireddefault: mp3enum: mp3, opus, wav, flacThe output format for the audio. Supported formats are mp3, opus, wav, and flac. Defaults to mp3.

bit\_rate

`integer`minimum: \-9007199254740991maximum: 9007199254740991Bits per second of the audio. Only for compressed audio formats (mp3, opus). The default is 128,000.

sample\_rate

`integer`minimum: \-9007199254740991maximum: 9007199254740991The synthesis sample rate in hertz. Accepts: 8000, 16000, 22050, 24000, 32000, 44100, 48000\. The default is 48,000.

speaking\_rate

`number`minimum: 0.5maximum: 1.5Speaking rate/speed, in the range \[0.5, 1.5\]. The default is 1.0\. We recommend using values above 0.8 to ensure high quality.

temperature

`number`requireddefault: 1minimum: 0.01maximum: 2Determines the degree of randomness when sampling audio tokens. Defaults to 1.0\. Accepts values between 0 (exclusive) and 2 (inclusive). Higher values = more expressive, lower values = more deterministic.

timestamp\_type

`string`requireddefault: noneenum: none, word, characterControls timestamp metadata returned with the audio. "word" returns word-level timing, "character" returns character-level timing. Note: adds latency. Defaults to none.

apply\_text\_normalization

`boolean`When enabled, text normalization expands numbers, dates, times, and abbreviations before converting to speech. Turning this off may reduce latency.

audio

`string`URL to the generated audio file

## API Schemas (Raw)

Input [ ](https://developers.cloudflare.com/ai/models/inworld/tts-1.5-mini/schema-input.json "Open") [ ](https://developers.cloudflare.com/ai/models/inworld/tts-1.5-mini/schema-input.json "Download") 

Output [ ](https://developers.cloudflare.com/ai/models/inworld/tts-1.5-mini/schema-output.json "Open") [ ](https://developers.cloudflare.com/ai/models/inworld/tts-1.5-mini/schema-output.json "Download")

```json
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```
