Language Detection

Language Detection identifies the language being spoken and scores its confidence in that answer. It produces no transcript, diarization, or enrichment data. The usual use is routing: read the language code off the response and send the audio to the matching downstream pipeline.

Language Detection (batch)

Returns application/json. Every field is always present.

Field	Type	Contents
`predicted_language`	string	Human-readable language name, such as `"English"`. Suitable for display.
`predicted_language_code`	string	Lowercase ISO 639-1 code, such as `"en"`. Suitable for routing, locale switching, or BCP 47 tags.
`confidence`	number	Probability for the predicted language, 0.0 to 1.0.
`duration_ms`	integer	Total duration of the decoded audio. Only the first 30 seconds are analyzed regardless of this value.

Try it

curl -X POST https://platform.modulate.ai/api/velma-2-language-detection-batch \
  -H "X-API-Key: $MODULATE_API_KEY" \
  -F "upload_file=@audio.mp3"

import os, requests

response = requests.post(
    "https://platform.modulate.ai/api/velma-2-language-detection-batch",
    headers={"X-API-Key": os.environ["MODULATE_API_KEY"]},
    files={"upload_file": open("audio.mp3", "rb")},
)
response.raise_for_status()
result = response.json()

print(f"{result['predicted_language']} ({result['predicted_language_code']}) "
      f"at {result['confidence']:.4f}")

import fs from "fs";
import FormData from "form-data";

const form = new FormData();
form.append("upload_file", fs.createReadStream("audio.mp3"), { filename: "audio.mp3" });

const response = await fetch(
  "https://platform.modulate.ai/api/velma-2-language-detection-batch",
  {
    method: "POST",
    headers: { "X-API-Key": process.env.MODULATE_API_KEY, ...form.getHeaders() },
    body: form,
  }
);

const result = await response.json();
console.log(`${result.predicted_language} (${result.predicted_language_code}) at ${result.confidence}`);

Response

{
  "predicted_language": "English",
  "predicted_language_code": "en",
  "confidence": 0.9847,
  "duration_ms": 14253
}

What you can configure

Form field	Default	Effect
`upload_file`	required	The audio to analyze. This endpoint takes no other parameters.

Audio formats

Accepted extensions: .aac, .aiff, .flac, .mov, .mp3, .mp4, .ogg, .opus, .wav, .webm. Maximum file size is 100 MB. Empty files are rejected with 400.

Behavior and constraints

Only the first 30 seconds of audio are analyzed. Longer files are accepted and the remainder is ignored, so duration_ms can exceed the analyzed span. Aim for at least 3 to 5 seconds of clear speech at the start. Audio in a language outside the supported set returns the closest supported match, usually with low confidence.

Acting on the confidence score

confidence near 1.0 means the model committed to an answer. Near 0.0 means it could not. There is no universally correct threshold; set one against how much misclassification the application can absorb.

result = response.json()

if result["confidence"] < 0.5:
    handle_unknown_language()
else:
    route_to_language_pipeline(result["predicted_language_code"])

Supported languages

100 spoken languages are recognized: Afrikaans, Albanian, Amharic, Arabic, Armenian, Assamese, Azerbaijani, Bashkir, Basque, Belarusian, Bengali, Bosnian, Breton, Bulgarian, Cantonese, Catalan, Chinese, Croatian, Czech, Danish, Dutch, English, Estonian, Faroese, Finnish, French, Galician, Georgian, German, Greek, Gujarati, Haitian Creole, Hausa, Hawaiian, Hebrew, Hindi, Hungarian, Icelandic, Indonesian, Italian, Japanese, Javanese, Kannada, Kazakh, Khmer, Korean, Lao, Latin, Latvian, Lingala, Lithuanian, Luxembourgish, Macedonian, Malagasy, Malay, Malayalam, Maltese, Maori, Marathi, Mongolian, Myanmar, Nepali, Norwegian, Nynorsk, Occitan, Pashto, Persian, Polish, Portuguese, Punjabi, Romanian, Russian, Sanskrit, Serbian, Shona, Sindhi, Sinhala, Slovak, Slovenian, Somali, Spanish, Sundanese, Swahili, Swedish, Tagalog, Tajik, Tamil, Tatar, Telugu, Thai, Tibetan, Turkish, Turkmen, Ukrainian, Urdu, Uzbek, Vietnamese, Welsh, Yiddish, Yoruba.

API reference

Language Detection Batch

Get started

By capability

Guides

Language Detection