---
title: "CLOVA Speech overview"
slug: "ai-application-service-clovaspeech"
updated: 2026-09-17T09:35:51Z
published: 2026-09-17T09:35:51Z
canonical: "api.ncloud-docs.com/ai-application-service-clovaspeech"
---

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

# CLOVA Speech overview

Available in Classic and VPC

CLOVA Speech is a NAVER Cloud Platform service that provides quick and easy speech recognition services through CLOVA's Neural End-to-end Speech Transcriber (NEST) speech recognition technology. It provides APIs in RESTful form for speech-based features such as transcribing long audio/video files, creating voice notes, video subtitles, and managing call transcripts.

              Note

              

CLOVA Speech service allows you to upload long audio/video files to check the speech recognition results. On the other hand, the CLOVA Speech Recognition (CSR) service is optimized for imperative speech recognition within one minute.

## Common CLOVA Speech settings

The following describes commonly used request and response formats in CLOVA Speech APIs.

### Request

The following describes the common request format.

#### API URL

The request API URL is as follows.

```
API Gateway's unique invoke URL created in CLOVA Speech Domain
```

              Note

              

For more information on how to check the InvokeURL, see [CLOVA Speech User Guide](https://guide.ncloud-docs.com/docs/en/clovaspeech-builder-long#api-%ED%98%B8%EC%B6%9C-%EC%A0%95%EB%B3%B4-%EB%B0%8F-%EB%8F%84%EB%A9%94%EC%9D%B8-%EC%A0%95%EB%B3%B4-%ED%99%95%EC%9D%B8).

#### Request headers

The following describes the headers.

| Field | Required | Description |
| --- | --- | --- |
| `Content-Type` | Required | Request data format - `application/json` \| `multipart/form-data` \| `application/octet-stream` |

### Response

The following describes the common response format.

#### Response status codes

The following describes the response status codes.

              Note

              

For response status codes common to NAVER Cloud Platform, see [Ncloud API response status codes](/docs/en/common-ncpapi#3%EC%9D%91%EB%8B%B5%EC%83%81%ED%83%9C%EC%BD%94%EB%93%9C).

| HTTP status code | Code | Message | Description |
| --- | --- | --- | --- |
| 400 | 400 | Invalid request parameters | Entered request parameter value is invalid |
| 401 | 401 | Invalid secret | Entered secret key value is invalid |
| 400 | STT002 | Invalid Content Type | `Content-Type` other than `application/octet-stream` is entered |
| 400 | STT003 | Empty Sound Data | Voice data missing |
| 400 | STT005 | Invalid Language | Entered language (`lang`) parameter not supported |
| 400 | STT004 | Empty Language | Language (`lang`) parameter missing |
| 413 | STT001 | Exceed Sound Data length | Entered voice data value exceeds the allowed length (60 seconds) |
| 500 | STT006 | Failed to pre-processing | Error during speech recognition preprocessing - Need to ensure voice data is legitimate `wav`, `mp3`, or `flac` |
| 500 | STT998 | Failed to STT | Error during speech recognition - Need to contact Support |
| 500 | STT999 | Internal Server Error | Internal server error - Need to contact Support |
| - | - | SUCCEEDED | Task successful |
| - | - | PROCESSING | Job in progress |
| - | - | ERROR_SERVER_BUSY | Server has no free resources |
| - | - | ERROR_TOKEN_INVALID | Token doesn't exist |
| - | - | ERROR_AUDIO_EMPTY | Voice data value doesn't exist |
| - | - | ERROR_AUDIO_CONVERSION | Failed to convert voice |
| - | - | ERROR_PARAMS_FORMAT_INVALID | Entered parameter format is not JSON |
| - | - | ERROR_REQUEST_PARAMETER | Entered request parameter is invalid |
| - | - | ERROR_REQUEST_PARAMETER | Speaker not recognized |
| - | - | ERROR_INVALID_SECRET | Entered secret key value is invalid |
| - | - | ERROR_DATA_NOT_FOUND | Internal server errors |
| - | - | ERROR_DATA_CONFLICT | Data conflict |
| - | - | ERROR_INTERNAL_ERROR | Internal server errors |
| - | - | ERROR_EXTERNAL_ERROR | Service not operational |
| - | - | ERROR_TOO_MANY_JOBS | Too many jobs |
| - | - | ERROR_GATEWAY_TIMEOUT | Timeout |
| - | - | FAILED | Other errors |

## CLOVA Speech API

The following describes the APIs provided by the CLOVA Speech service.

| API | Description |
| --- | --- |
| [Long sentence recognition > Object Storage file recognition](/docs/en/ai-application-service-clovaspeech-longsentence) | Recognize long text as unique URLs of media files stored in Object Storage on NAVER Cloud Platform |
| [Long sentence recognition > External file recognition](/docs/en/ai-application-service-clovaspeech-longsentence-externalurl) | Recognize long text from unique URLs of publicly available audio files |
| [Long sentence recognition > Local file recognition](/docs/en/ai-application-service-clovaspeech-longsentence-local) | Recognize long text for local files |
| [Long sentence recognition > Get job status](/docs/en/ai-application-service-clovaspeech-longsentence-getjobstatus) | Check the job status asynchronously |
| [Short sentence recognition](/docs/en/ai-application-service-clovaspeech-shortsentence) | Recognize short voice files up to 60 seconds long |
| [Live streaming recognition](/docs/en/ai-application-service-clovaspeech-grpc) | Real-time speech recognition and text-to-speech |

## CLOVA Speech related resources

NAVER Cloud Platform provides a variety of related resources to help users better understand CLOVA Speech APIs.

- CLOVA Speech API guides
  - [Common Ncloud response status codes](/docs/en/common-ncpapi#3-%EC%9D%91%EB%8B%B5-%EC%83%81%ED%83%9C-%EC%BD%94%EB%93%9C): information on common response status codes of NAVER Cloud Platform used by the CLOVA Speech service
  - [Object Storage User Guide](https://guide.ncloud-docs.com/docs/en/storage-storage-6-1): how to use Object Storage required for the use of CLOVA Speech
  - [Sub Account User Guide](https://guide.ncloud-docs.com/docs/en/subaccount-overview): how to use Sub Account that helps the management of CLOVA Speech's administration permissions
- How to use the CLOVA Speech service
  - [CLOVA Speech User Guide](https://guide.ncloud-docs.com/docs/en/clovaspeech-overview): how to use the CLOVA Speech service, check usage, and set up notifications in NAVER Cloud Platform console
  - [Prerequisites for using CLOVA Speech](https://guide.ncloud-docs.com/docs/en/clovaspeech-spec): supported specifications, limitations, and usage fees in order to use CLOVA Speech
  - [Ncloud use environment guide](https://guide.ncloud-docs.com/docs/en/environment-environment-1-1): guide on VPC and Classic environments and supported features
  - [Introduction to pricing, characteristics, and detailed features](https://www.ncloud.com/product/aiService/clovaSpeech): summary of CLOVA Speech pricing system, characteristics, and detailed features of CLOVA Speech
  - [Latest service news](https://www.ncloud.com/intro/news): the latest news on CLOVA Speech
  - [FAQ](https://www.ncloud.com/support/faq/prod?categoryCode2=AI&categoryCode3=SV_0055&page=1): frequently asked questions from CLOVA Speech users
  - [Contact Us](https://www.ncloud.com/support/question/service): Send direct inquiries in case of any unresolved questions that aren't answered by the user guides.