---
title: Eleven Monolingual v1 | Runware Docs
url: https://runware.ai/docs/models/elevenlabs-monolingual-v1
description: English TTS model for clear natural speech output
---
# Eleven Monolingual v1

Eleven Monolingual v1 is an English only text to speech model from ElevenLabs. It focuses on simple natural delivery and stable output. Ideal for lightweight applications, legacy integrations, or projects that need predictable English voice synthesis with low complexity.

- **ID**: `elevenlabs:20@1`
- **Status**: live
- **Creator**: ElevenLabs
- **Release Date**: May 27, 2025
- **Capabilities**: Text to Audio

## Request Parameters

**API Options**

Platform-level options for task execution and delivery.

### [taskType](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-tasktype)

- **Type**: `string`
- **Required**: true
- **Value**: `audioInference`

Identifier for the type of task being performed

### [taskUUID](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-taskuuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID v4 identifier for tracking tasks and matching async responses. Must be unique per task.

### [outputType](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-outputtype)

- **Type**: `string`
- **Default**: `URL`

Audio output type.

**Allowed values**: `URL` `base64Data` `dataURI`

### [outputFormat](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-outputformat)

- **Type**: `string`
- **Default**: `MP3`

Specifies the file format of the generated output. The available values depend on the task type and the specific model's capabilities.

- \`MP3\`: Compressed audio, smaller file size.
- \`WAV\`: Uncompressed, high-quality audio.
- \`FLAC\`: Lossless compression.
- \`OGG\`: Open-source compressed audio format (Vorbis codec).

**Allowed values**: `MP3` `WAV` `FLAC` `OGG`

### [audioSettings](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-audiosettings)

- **Path**: `audioSettings.bitrate`
- **Type**: `object (3 properties)`

Audio encoding settings for controlling the bitrate, number of channels, and sample rate of the generated audio. Only applicable for lossy output formats (`MP3` and `OGG`). When using lossless formats (`WAV` or `FLAC`), this parameter must not be provided.

The available sample rates and valid bitrate ranges depend on the output format. For `OGG`, bitrate limits also vary by the number of channels.

**MP3 bitrate limits**:

Bitrate limits for MP3 are the same regardless of mono or stereo.

| Sample Rate | Min Bitrate | Max Bitrate |
| --- | --- | --- |
| 8,000 Hz | 8 kbps | 64 kbps |
| 11,025 Hz | 8 kbps | 64 kbps |
| 12,000 Hz | 8 kbps | 64 kbps |
| 16,000 Hz | 8 kbps | 160 kbps |
| 22,050 Hz | 8 kbps | 160 kbps |
| 24,000 Hz | 8 kbps | 160 kbps |
| 32,000 Hz | 32 kbps | 320 kbps |
| 44,100 Hz | 32 kbps | 320 kbps |
| 48,000 Hz | 32 kbps | 320 kbps |

**OGG bitrate limits — Mono (1 channel)**:

| Sample Rate | Min Bitrate | Max Bitrate |
| --- | --- | --- |
| 8,000 Hz | 8 kbps | 40 kbps |
| 12,000 Hz | 16 kbps | 48 kbps |
| 16,000 Hz | 16 kbps | 96 kbps |
| 24,000 Hz | 16 kbps | 80 kbps |
| 48,000 Hz | 32 kbps | 224 kbps |

**OGG bitrate limits — Stereo (2 channels)**:

| Sample Rate | Min Bitrate | Max Bitrate |
| --- | --- | --- |
| 8,000 Hz | 16 kbps | 80 kbps |
| 12,000 Hz | 16 kbps | 96 kbps |
| 16,000 Hz | 24 kbps | 192 kbps |
| 24,000 Hz | 32 kbps | 160 kbps |
| 48,000 Hz | 48 kbps | 256 kbps |

> [!NOTE]
> **Lossless formats**: When `outputFormat` is set to `WAV` or `FLAC`, the `audioSettings` parameter is not available since these formats produce uncompressed or lossless audio with no configurable encoding settings.

#### [bitrate](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-audiosettings-bitrate)

- **Path**: `audioSettings.bitrate`
- **Type**: `integer`
- **Min**: `8`

Audio bitrate in kbps.

#### [channels](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-audiosettings-channels)

- **Path**: `audioSettings.channels`
- **Type**: `integer`
- **Default**: `2`

Number of audio channels. 1 for mono, 2 for stereo.

**Allowed values**: `1` `2`

#### [sampleRate](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-audiosettings-samplerate)

- **Path**: `audioSettings.sampleRate`
- **Type**: `integer`

Audio sample rate in Hz.

### [webhookURL](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-webhookurl)

- **Type**: `string`
- **Format**: `URI`

Specifies a webhook URL where JSON responses will be sent via HTTP POST when generation tasks complete. For batch requests with multiple results, each completed item triggers a separate webhook call as it becomes available.

**Learn more** (1 resource):

- [Webhooks](https://runware.ai/docs/platform/webhooks) (platform)

### [deliveryMethod](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-deliverymethod)

- **Type**: `string`
- **Default**: `sync`

Determines how the API delivers task results.

**Allowed values**:

- `sync` Returns complete results directly in the API response.
- `async` Returns an immediate acknowledgment with the task UUID. Poll for results using getResponse.

**Learn more** (1 resource):

- [Task Polling](https://runware.ai/docs/platform/task-polling) (platform)

### [uploadEndpoint](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-uploadendpoint)

- **Type**: `string`
- **Format**: `URI`

Specifies a URL where the generated content will be automatically uploaded using the HTTP PUT method. The raw binary data of the media file is sent directly as the request body. For secure uploads to cloud storage, use presigned URLs that include temporary authentication credentials.

**Common use cases:**

- **Cloud storage**: Upload directly to S3 buckets, Google Cloud Storage, or Azure Blob Storage using presigned URLs.
- **CDN integration**: Upload to content delivery networks for immediate distribution.

```text
// S3 presigned URL for secure upload
https://your-bucket.s3.amazonaws.com/generated/content.mp4?X-Amz-Signature=abc123&X-Amz-Expires=3600

// Google Cloud Storage presigned URL
https://storage.googleapis.com/your-bucket/content.jpg?X-Goog-Signature=xyz789

// Custom storage endpoint
https://storage.example.com/uploads/generated-image.jpg
```

The content data will be sent as the request body to the specified URL when generation is complete.

### [ttl](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-ttl)

- **Type**: `integer`
- **Min**: `60`

Time-to-live (TTL) in seconds for generated content. Only applies when `outputType` is `URL`.

### [includeCost](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-includecost)

- **Type**: `boolean`
- **Default**: `false`

Include task cost in the response.

### [numberResults](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-numberresults)

- **Type**: `integer`
- **Min**: `1`
- **Max**: `4`
- **Default**: `1`

Number of results to generate. Each result uses a different seed, producing variations of the same parameters.

**Generation Parameters**

Core parameters for controlling the generated content.

### [model](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-model)

- **Type**: `string`
- **Required**: true
- **Value**: `elevenlabs:20@1`

Identifier of the model to use for generation.

**Learn more** (3 resources):

- [Text To Image: Model Selection The Foundation Of Generation](https://runware.ai/docs/guides/text-to-image#model-selection-the-foundation-of-generation) (guide)
- [Image Inpainting: Model Specialized Inpainting Models](https://runware.ai/docs/guides/image-inpainting#model-specialized-inpainting-models) (guide)
- [Image Outpainting: Other Critical Parameters](https://runware.ai/docs/guides/image-outpainting#other-critical-parameters) (guide)

### [seed](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-seed)

- **Type**: `integer`
- **Min**: `0`
- **Max**: `4294967295`

Random seed for reproducible generation. When not provided, a random seed is generated in the unsigned 32-bit range.

### [speech](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-speech)

- **Path**: `speech.text`
- **Type**: `object (2 properties)`
- **Required**: true

Settings for speech generation.

#### [text](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-speech-text)

- **Path**: `speech.text`
- **Type**: `string`
- **Max**: `10000`

Text to convert to speech.

#### [language](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-speech-language)

- **Path**: `speech.language`
- **Type**: `string`
- **Min**: `1`

Language code for speech generation.

**Allowed values**: `en`

**Provider Settings**

Parameters specific to this model provider. These must be nested inside the \`providerSettings.elevenlabs\` object.

### [textToSpeech](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech)

- **Path**: `providerSettings.elevenlabs.textToSpeech`
- **Type**: `object (9 properties)`

Provider-specific settings for ElevenLabs text-to-speech generation.

#### [voiceSettings](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-voicesettings)

- **Path**: `providerSettings.elevenlabs.textToSpeech.voiceSettings`
- **Type**: `object (4 properties)`

Voice settings overriding stored settings for the given voice. Applied only on the given request.

##### [stability](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-voicesettings-stability)

- **Path**: `providerSettings.elevenlabs.textToSpeech.voiceSettings.stability`
- **Type**: `float`
- **Min**: `0`
- **Max**: `1`

Controls voice stability and randomness between each generation. Lower values introduce broader emotional range, higher values produce a more consistent tone.

##### [useSpeakerBoost](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-voicesettings-usespeakerboost)

- **Path**: `providerSettings.elevenlabs.textToSpeech.voiceSettings.useSpeakerBoost`
- **Type**: `boolean`

Boosts similarity to the original speaker at a slight increase in computational load and latency.

##### [similarityBoost](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-voicesettings-similarityboost)

- **Path**: `providerSettings.elevenlabs.textToSpeech.voiceSettings.similarityBoost`
- **Type**: `float`
- **Min**: `0`
- **Max**: `1`

Controls how closely the AI adheres to the original voice when attempting to replicate it.

##### [style](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-voicesettings-style)

- **Path**: `providerSettings.elevenlabs.textToSpeech.voiceSettings.style`
- **Type**: `float`
- **Min**: `0`
- **Max**: `1`

Controls style exaggeration of the voice. Higher values amplify the style of the original speaker but may increase latency.

#### [previousText](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-previoustext)

- **Path**: `providerSettings.elevenlabs.textToSpeech.previousText`
- **Type**: `string`
- **Max**: `1000`

Text that came before the current request. Improves speech continuity when concatenating multiple generations.

#### [nextText](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-nexttext)

- **Path**: `providerSettings.elevenlabs.textToSpeech.nextText`
- **Type**: `string`
- **Max**: `1000`

Text that comes after the current request. Improves speech continuity when concatenating multiple generations.

#### [applyTextNormalization](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-applytextnormalization)

- **Path**: `providerSettings.elevenlabs.textToSpeech.applyTextNormalization`
- **Type**: `string`
- **Default**: `auto`

Controls text normalization behavior (e.g., spelling out numbers).

**Allowed values**:

- `auto` Automatically decides whether to apply text normalization.
- `on` Always applies text normalization.
- `off` Skips text normalization entirely.

#### [applyLanguageTextNormalization](https://runware.ai/docs/models/elevenlabs-monolingual-v1#request-providersettings-elevenlabs-texttospeech-applylanguagetextnormalization)

- **Path**: `providerSettings.elevenlabs.textToSpeech.applyLanguageTextNormalization`
- **Type**: `boolean`
- **Default**: `false`

Enables language-specific text normalization for proper pronunciation. Currently only supported for Japanese. Warning: can significantly increase latency.

## Response Parameters

### [taskType](https://runware.ai/docs/models/elevenlabs-monolingual-v1#response-tasktype)

- **Type**: `string`
- **Required**: true
- **Value**: `audioInference`

Type of the task.

### [taskUUID](https://runware.ai/docs/models/elevenlabs-monolingual-v1#response-taskuuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID of the task.

### [audioUUID](https://runware.ai/docs/models/elevenlabs-monolingual-v1#response-audiouuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID of the output audio.

### [audioURL](https://runware.ai/docs/models/elevenlabs-monolingual-v1#response-audiourl)

- **Type**: `string`
- **Format**: `URI`

URL of the output audio.

### [audioBase64Data](https://runware.ai/docs/models/elevenlabs-monolingual-v1#response-audiobase64data)

- **Type**: `string`

Base64-encoded audio data.

### [audioDataURI](https://runware.ai/docs/models/elevenlabs-monolingual-v1#response-audiodatauri)

- **Type**: `string`
- **Format**: `URI`

Data URI of the output audio.

### [seed](https://runware.ai/docs/models/elevenlabs-monolingual-v1#response-seed)

- **Type**: `integer`

The seed used for generation. If none was provided, shows the randomly generated seed.

### [cost](https://runware.ai/docs/models/elevenlabs-monolingual-v1#response-cost)

- **Type**: `float`

Task cost in USD. Present when `includeCost` is set to `true` in the request.

## Examples

### Crackling Deep-Space Distress Log (Text to Audio)

[Listen to audio](https://assets.runware.ai/examples/elevenlabs-monolingual-v1/d183e29c-c953-43d0-b7c3-0b7fb04aa18c.mp3)

**Request**:

```json
{
  "taskType": "audioInference",
  "taskUUID": "6ef33047-6d9c-4510-8cee-bd1f208d7486",
  "model": "elevenlabs:20@1",
  "seed": 46384,
  "speech": {
    "text": "Command, this is survey vessel Arden Nine. If this reaches anyone, our navigation array failed after the second flare. We are drifting beyond the mapped corridor with power restricted to life support, telemetry, and one narrow-band transmitter. The crew is conscious. Oxygen reserves are limited, but morale is holding. We have marked our current vector against the red giant in the Perseus reach and released three signal beacons at seven-minute intervals. Please advise any rescue traffic to avoid the debris field to our stern. Repeating final coordinates now. Arden Nine standing by.",
    "language": "en"
  },
  "providerSettings": {
    "elevenlabs": {
      "textToSpeech": {
        "voiceSettings": {
          "stability": 0.78,
          "similarityBoost": 0.72,
          "style": 0.22,
          "useSpeakerBoost": true
        },
        "applyTextNormalization": "auto",
        "previousText": "Emergency channel open. Priority traffic only.",
        "nextText": "End of transmission. Awaiting response."
      }
    }
  }
}
```

**Response**:

```json
{
  "taskType": "audioInference",
  "taskUUID": "6ef33047-6d9c-4510-8cee-bd1f208d7486",
  "audioUUID": "055acc7f-dcb5-43bb-afdd-407f2acac9fb",
  "audioURL": "https://am.runware.ai/audio/os/a23d05/ws/5/ai/055acc7f-dcb5-43bb-afdd-407f2acac9fb.mp3",
  "seed": 46384,
  "cost": 0.09136
}
```

---

### Antique Phonograph Museum Guide (Text to Audio)

[Listen to audio](https://assets.runware.ai/examples/elevenlabs-monolingual-v1/d6b71310-bc26-4808-824c-35e02cbaa9ab.mp3)

**Request**:

```json
{
  "taskType": "audioInference",
  "taskUUID": "baec74ad-0310-4120-a3ca-3d8abc10c3c6",
  "model": "elevenlabs:20@1",
  "seed": 99331,
  "speech": {
    "text": "Welcome to Gallery Three, home of the singing machines. In front of you is an early phonograph with a polished brass horn and a hand-cranked motor. Visitors often expect a rich modern sound, but these devices produced a narrow, scratchy signal that listeners of the time still found astonishing. Imagine hearing a human voice replay itself from a wax cylinder for the very first time. To your left is a later home model, built to make recorded music part of ordinary evenings. Notice how the cabinet becomes more refined, hiding the mechanism inside furniture so the machine feels less industrial and more domestic. Before you move on, look closely at the tiny grooves in the recording medium. Those delicate lines carried speeches, comic routines, and parlor songs across years of handling and travel. When you are ready, continue to the next room for the early era of broadcast receivers.",
    "language": "en"
  },
  "providerSettings": {
    "elevenlabs": {
      "textToSpeech": {
        "voiceSettings": {
          "stability": 0.82,
          "similarityBoost": 0.72,
          "style": 0.18,
          "useSpeakerBoost": true
        },
        "applyTextNormalization": "auto",
        "previousText": "This wing explores inventions that changed how people listened at home.",
        "nextText": "The next section examines how radio transformed news, entertainment, and public life."
      }
    }
  }
}
```

**Response**:

```json
{
  "taskType": "audioInference",
  "taskUUID": "baec74ad-0310-4120-a3ca-3d8abc10c3c6",
  "audioUUID": "b26b0669-87c0-4ff9-b1ac-653c8011ffc3",
  "audioURL": "https://am.runware.ai/audio/os/a04d20/ws/5/ai/b26b0669-87c0-4ff9-b1ac-653c8011ffc3.mp3",
  "seed": 99331,
  "cost": 0.13675
}
```

---

### Subterranean Transit Safety Announcement (Text to Audio)

[Listen to audio](https://assets.runware.ai/examples/elevenlabs-monolingual-v1/8d440e2d-3012-47f7-af33-03edb39472f5.mp3)

**Request**:

```json
{
  "taskType": "audioInference",
  "taskUUID": "bd9e333e-4f11-4e9c-8b44-cd6ed76e36dc",
  "model": "elevenlabs:20@1",
  "seed": 64131,
  "speech": {
    "text": "Attention passengers. This is a service update for Platform C. The 7:15 inbound train to Ashgrove has been delayed by approximately 12 minutes due to signal checks near Harbor Junction. For the fastest alternate route, board the 7:18 shuttle service from Bay 4 and transfer at Central Exchange. Please stand behind the yellow line, keep aisles clear, and allow exiting passengers to step off before boarding. If you require accessibility assistance, press the blue help point or speak with a station attendant. We appreciate your patience and cooperation.",
    "language": "en"
  },
  "providerSettings": {
    "elevenlabs": {
      "textToSpeech": {
        "voiceSettings": {
          "stability": 0.82,
          "similarityBoost": 0.72,
          "style": 0.18,
          "useSpeakerBoost": true
        },
        "applyTextNormalization": "on"
      }
    }
  }
}
```

**Response**:

```json
{
  "taskType": "audioInference",
  "taskUUID": "bd9e333e-4f11-4e9c-8b44-cd6ed76e36dc",
  "audioUUID": "a04c8311-2c32-4b32-b47b-60410014140f",
  "audioURL": "https://am.runware.ai/audio/os/a17d13/ws/5/ai/a04c8311-2c32-4b32-b47b-60410014140f.mp3",
  "seed": 64131,
  "cost": 0.08451
}
```

---

### Harbor Evacuation Ferry Bulletin (Text to Audio)

[Listen to audio](https://assets.runware.ai/examples/elevenlabs-monolingual-v1/8057abf2-ed3d-4d15-b17c-9f5991373d0e.mp3)

**Request**:

```json
{
  "taskType": "audioInference",
  "taskUUID": "04002268-d5f5-4e88-8b41-a12bac953653",
  "model": "elevenlabs:20@1",
  "seed": 75211,
  "speech": {
    "text": "Attention passengers at Pier Seven. Due to a chemical spill on the east access road, all private vehicle pickup has been suspended until further notice. Please remain inside the marked waiting zone and listen carefully for your boarding group. Families traveling with children, passengers using mobility aids, and anyone holding a blue priority ticket will board first for the 6:40 departure to North Haven. Group B will follow immediately after. Do not approach the loading ramp until your group is called. For your safety, leave all bicycles, carts, and oversized luggage against the orange barrier for crew inspection. If you feel dizzy, short of breath, or need medication from a stored bag, notify a dock attendant right away. Again, this is a controlled evacuation transfer to North Haven. Stay calm, keep the center aisle open, and await further instructions.",
    "language": "en"
  },
  "providerSettings": {
    "elevenlabs": {
      "textToSpeech": {
        "voiceSettings": {
          "stability": 0.82,
          "similarityBoost": 0.72,
          "style": 0.18,
          "useSpeakerBoost": true
        },
        "applyTextNormalization": "on"
      }
    }
  }
}
```

**Response**:

```json
{
  "taskType": "audioInference",
  "taskUUID": "04002268-d5f5-4e88-8b41-a12bac953653",
  "audioUUID": "689f9690-2d0b-4af6-98e2-a7672c88db5a",
  "audioURL": "https://am.runware.ai/audio/os/a10d08/ws/5/ai/689f9690-2d0b-4af6-98e2-a7672c88db5a.mp3",
  "seed": 75211,
  "cost": 0.13153
}
```