---
title: "CLOVA OCR overview"
slug: "ai-application-service-ocr"
tags: ["CLOVA OCR", "overview"]
updated: 2026-09-17T09:35:51Z
published: 2026-09-17T09:35:51Z
canonical: "api.ncloud-docs.com/ai-application-service-ocr"
---

> ## 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 OCR overview

Available in Classic and VPC

CLOVA OCR (Optical Character Recognition) is a NAVER Cloud Platform service that recognizes transmitted documents or images and accurately extracts text and data in user-specified areas. It provides APIs in RESTful form for recognizing all text in images, recognizing text in images with templates deployed in a domain, and quickly extracting only the required text within a template.

## Common CLOVA OCR settings

The following describes commonly used request and response formats in CLOVA OCR 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 OCR Builder
```

              Note

              

To check the invoke URL, see the [CLOVA OCR User Guide](https://guide.ncloud-docs.com/docs/en/clovaocr-domain#api-gateway-%EC%97%B0%EB%8F%99).

#### Request headers

The following describes the headers.

| Field | Required | Description |
| --- | --- | --- |
| `X-OCR-SECRET` | Required | Client secret created in NAVER Cloud Platform domain when integrating with API Gateway |
| `Content-Type` | Required | Request data format - `application/json` \| `multipart/form-data` |

### Response

The following describes the common response format.

#### Response status codes

The following describes the response status codes.

| HTTP status code | Code | Message | Description |
| --- | --- | --- | --- |
| 400 | 0001 | URL is invalid. | Invalid call URL entered. - Check that the POST URL you called is correct. |
| 401 | 0002 | Secret key validate failed. | Entered secret key not validated. - Check if the `X-OCR-SECRET:{Client Secret}` value is accurate. |
| 400 | 0011 | Request body invalid. | Entered request body value is invalid. |
| 400 | 0021 | Protocol version not support. | Unsupported API version. |
| 400 | 0022 | Request domain invalid. | Entered request domain value is invalid. |
| 400 | 0023 | API request count reach the upper limit. | API call limit reached. |
| 400 | 0025 | Calls to this api have exceeded the rate limit. | API call count exceeds rate limit. |
| 400 | 0028 | Table detection disabled: Please activate the table extractor button. | Called with enableTableDetection: true under the table extration status of OFF. |
| 500 | 0500 | Unknown service error. | Unknown service error occurred. |
| 500 | 0501 | OCR service error. | OCR service error occurred. |
| 500 | 1021 | Not found deploy information. Please confirm the template is released. | Template deployment history not found. - Need to check whether the template is deployed to the domain in NAVER Cloud Platform console. |
| 500 | 1022 | Service is blocked. | Service temporarily unavailable. |

              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).

## CLOVA OCR API

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

| API | Description |
| --- | --- |
| [General OCR](/docs/en/ai-application-service-ocr-ocr) | Plain text and table extraction OCR |
| [Template OCR](/docs/en/clova-template-ocr-api) | Template OCR |
| [Document OCR > Business card](/docs/en/ai-application-service-ocr-ocrdocumentocr) | Business card information OCR |
| [Document OCR > Business registration certificate](/docs/en/ai-application-service-ocr-ocrdocumentocr-bizlicense) | Business registration certificate information OCR |
| [Document OCR > Credit card](/docs/en/ai-application-service-ocr-ocrdocumentocr-creditcard) | Credit card information OCR |
| [Document OCR > Receipt](/docs/en/ai-application-service-ocr-ocrdocumentocr-receipt) | Receipt information OCR |
| [Document OCR > ID card > Passport](/docs/en/ai-application-service-ocr-ocrdocumentocr-passport) | Passport information OCR |
| [Document OCR > ID card > Alien registration card](/docs/en/ai-application-service-ocr-ocrdocumentocr-alienregistration) | Alien registration card information OCR |
| [Document OCR > ID card > Driver's license](/docs/en/ai-application-service-ocr-ocrdocumentocr-driverlicense) | Driver's license information OCR |
| [Document OCR > ID card > Resident registration card](/docs/en/ai-application-service-ocr-ocrdocumentocr-identitycard) | Resident registration card information OCR |

## CLOVA OCR related resources

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

- CLOVA OCR 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 OCR service
  - [API Gateway User Guide](https://guide.ncloud-docs.com/docs/en/apigw-apigw-1): how to use API Gateway required for calling CLOVA OCR APIs
  - [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 OCR
  - [Sub Account User Guide](https://guide.ncloud-docs.com/docs/en/subaccount-overview): how to use Sub Account that helps the management of CLOVA OCR's administration permissions
  - [Call Text OCR API](https://guide.ncloud-docs.com/docs/en/clovaocr-example01): introduction to calling Text OCR API
- How to use the CLOVA OCR service
  - [CLOVA OCR User Guide](https://guide.ncloud-docs.com/docs/en/clovaocr-overview): how to use the CLOVA OCR service, create and manage batches (batch processing of large volumes of images), check usage, and set up notifications in NAVER Cloud Platform console
  - [Prerequisites for using CLOVA OCR](https://guide.ncloud-docs.com/docs/en/clovaocr-spec): supported specifications, limitations, and usage fees in order to use CLOVA OCR
  - [OCR Reader](https://guide.ncloud-docs.com/docs/en/clovaocr-ocrreader): how to use the OCR Reader
  - [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/ocr): summary of CLOVA OCR pricing system, characteristics, and detailed features of CLOVA OCR
  - [Latest service news](https://www.ncloud.com/intro/news): the latest news on CLOVA OCR
  - [FAQ](https://www.ncloud.com/support/faq/prod?categoryCode2=AI&categoryCode3=SV_0055&page=1): frequently asked questions from CLOVA OCR 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.