***

title: Language detection
description: Automatically detect and transcribe 30+ languages with Pulse STT
-----------------------------------------------------------------------------

<Badge color="green">
  Pre-Recorded
</Badge>

<Badge color="purple">
  Real-Time
</Badge>

## Enabling language detection

Set the `language` query parameter to `multi` when calling the API. It will auto-detect the spoken language across 30+ ISO 639-1 language codes.

<Note>
  View the full list of [supported languages](../overview#supported-languages).
</Note>

### Pre-Recorded API

```bash
curl --request POST \
  --url "https://waves-api.smallest.ai/api/v1/pulse/get_text?model=pulse&language=multi&word_timestamps=true" \
  --header "Authorization: Bearer $SMALLEST_API_KEY" \
  --header "Content-Type: audio/wav" \
  --data-binary "@/path/to/audio.wav"
```

### Real-Time WebSocket API

```javascript
const url = new URL("wss://waves-api.smallest.ai/api/v1/pulse/get_text");
url.searchParams.append("language", "multi");
url.searchParams.append("encoding", "linear16");
url.searchParams.append("sample_rate", "16000");

const ws = new WebSocket(url.toString(), {
  headers: {
    Authorization: `Bearer ${API_KEY}`,
  },
});
```

## Output format & field of interest

When language detection is enabled, the `transcription` (or `transcript` for realtime), `words`, and `utterances` arrays are emitted in the detected language. The response includes a `language` field with the detected primary language code, and a `languages` array (in realtime responses where `is_final=true`) listing all detected languages. Persist the detected locale in your app by storing the `language` parameter you supplied (for auditing) and by inspecting downstream metadata such as subtitles or captions that inherit the localized transcript.

## Sample response

### Pre-Recorded API Response

```json
{
  "status": "success",
  "transcription": "Hola mundo.",
  "words": [
    { "start": 0.0, "end": 0.4, "word": "Hola" },
    { "start": 0.5, "end": 0.9, "word": "mundo." }
  ],
  "utterances": [
    { "text": "Hola mundo.", "start": 0.0, "end": 0.9 }
  ]
}
```

### Real-Time WebSocket API Response

```json
{
  "session_id": "sess_12345abcde",
  "transcript": "Hola mundo.",
  "is_final": true,
  "is_last": false,
  "language": "es",
  "languages": ["es"]
}
```

<Note>
  The `language` field is only returned when `is_final=true` in real-time API responses. The `languages` array lists all languages detected in the audio and is also only included when `is_final=true`.
</Note>