# Overview

The Language Identification API provides additional speech insights by identifying the spoken language in a given transcript.

## API endpoint

The base URL for this version of the API is `https://api.rev.ai/languageid/v1/`. All endpoints described in this documentation are relative to this base URL.

The base URL for this version of the API differs for non-US deployments. Users working with non-US deployments should obtain the correct base URL for their deployment from the [Rev AI global deployments](/api/global-deployments) page.

## Authentication

Clients must authenticate by including their [Rev AI access token](/api/security#access-token) as a query parameter in their requests. If the access token is invalid or the query parameter is not present, a `401` error code will be returned.

## Confidence scores

The confidence scores in a result represent how confident our model is that the given language is the language spoken in the submitted audio. This score is always a numeric value in the range [0, 1].

## Turnaround time

The average turnaround time ranges from 0.01 to 0.1 second for every 1 second of input audio. This means that, for example, given an input audio file of 30 seconds duration, turnaround time would range from 0.3 seconds to 3 seconds on average.

The maximum possible turnaround time for a job is 2 hours. Jobs which exceed this time limit will be automatically marked as failed.

An important point to note here is that the turnaround time is influenced by two variables: the job overhead (constant) and the audio length (variable). As a quick rule of thumb, the following table illustrates average turnaround times for different audio lengths:

| Audio length | Average turnaround time (seconds) |
|  --- | --- |
| 1 minute | 10.2 seconds |
| 2 minutes | 4.8 seconds |
| 5 minutes | 7.5 seconds |
| 10 minutes | 12 seconds |
| 30 minutes | 27 seconds |
| 60 minutes | 36 seconds |
| 5 hours | 90 seconds |


If you require faster turnaround time or assistance with failed jobs, please contact the support team at [support@rev.ai](mailto:support@rev.ai).