> ## Documentation Index
> Fetch the complete documentation index at: https://docs.snapgen.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Eleven Flash v2.5

> Low-cost ElevenLabs Flash v2.5 text to speech, up to 40,000 characters per request. $0.06 per 1,000 characters.

`eleven-flash-v2.5` runs ElevenLabs Flash v2.5 text to speech. It costs half as much per character as the other speech models and accepts the most text: up to 40,000 characters per request.

| Property | Value |
| - | - |
| Model ID | `eleven-flash-v2.5` |
| Endpoint | `POST /v1/audio/speech` |
| Output | Audio bytes: MP3 (default), Opus, PCM, or WAV |
| Limits | Up to 40,000 characters per request |
| Billed on | Characters of `input` |
| Price | \$0.06 per 1,000 characters (6 credits) |

Confirm live rates on the [SnapGen models page](https://snapgen.org/models). Failed requests are not charged.

<ParamField body="model" type="string" required>
  Set to `eleven-flash-v2.5`.
</ParamField>

<ParamField body="input" type="string" required>
  The text to speak, up to 40,000 characters for this model. Newlines are allowed; blank text and other control characters are rejected. Each character is billed.
</ParamField>

<ParamField body="voice" type="string" required>
  A voice ID or first name from the [voice list](/api-reference/audio-speech#voices), for example `JBFqnCBsd6RMkjVDRZzb` or `George`. Names are case-insensitive.
</ParamField>

<ParamField body="response_format" type="string" default="mp3">
  `mp3`, `opus`, `pcm`, or `wav`. See [Output formats](/api-reference/audio-speech#output-formats).
</ParamField>

<ParamField body="speed" type="number">
  Speaking speed, from `0.7` to `1.2`.
</ParamField>

<ParamField body="language" type="string">
  An ISO 639 language code of two or three lowercase letters, such as `en` or `de`. The provider rejects a code the model doesn't support.
</ParamField>

<ParamField body="stability" type="number">
  From `0` to `1`. Lower values give a broader emotional range; higher values sound more consistent.
</ParamField>

<ParamField body="similarity_boost" type="number">
  From `0` to `1`. How closely the output follows the original voice.
</ParamField>

<ParamField body="style" type="number">
  From `0` to `1`. Exaggerates the voice's speaking style.
</ParamField>

<ParamField body="use_speaker_boost" type="boolean">
  Boosts similarity to the original speaker.
</ParamField>

<ParamField body="seed" type="integer">
  From `0` to `4294967295`. Makes repeated requests more repeatable, without guaranteeing identical audio.
</ParamField>

<ParamField body="previous_text" type="string">
  Up to 5,000 characters that come before `input`, for continuity across requests. Not billed.
</ParamField>

<ParamField body="next_text" type="string">
  Up to 5,000 characters that follow `input`, for continuity across requests. Not billed.
</ParamField>

<ParamField body="apply_text_normalization" type="string">
  `auto`, `on`, or `off`: whether numbers, dates, and similar text are spelled out before speaking.
</ParamField>

## Request

```bash theme={null}
curl https://api.snapgen.org/v1/audio/speech \
  -H "Authorization: Bearer $SNAPGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "eleven-flash-v2.5",
    "input": "Welcome back! Today we explore the northern lights.",
    "voice": "JBFqnCBsd6RMkjVDRZzb",
    "response_format": "mp3"
  }' \
  --output speech.mp3
```

The response body is the audio file, with a `Content-Type` that matches `response_format`.

## Price examples

| Text | Price |
| - | - |
| 100 characters | \$0.006 |
| 1,000 characters | \$0.06 |
| 40,000 characters | \$2.40 |

<Note>
  Synchronous audio endpoints reject `Idempotency-Key`. If a request times out, check your Console request logs before you retry.
  See [Text to speech](/api-reference/audio-speech) for every field, the response, and errors.
</Note>