Image Caption API

Overview

To use Image Caption, you need an API key. You can get one by creating a free account and visiting your dashboard.

POST Endpoint

https://api.apiverve.com/v1/imagecaption

Example

How to call the Image Caption API in different programming languages.

curl -X POST \
  "https://api.apiverve.com/v1/imagecaption" \
  -H "X-API-Key: your_api_key_here" \
  -F "image=@/path/to/image.jpg"

const formData = new FormData();
formData.append('image', fileInput.files[0]);

const response = await fetch('https://api.apiverve.com/v1/imagecaption', {
  method: 'POST',
  headers: {
    'X-API-Key': 'your_api_key_here'
  },
  body: formData
});

const data = await response.json();
console.log(data);

import requests

headers = {
    'X-API-Key': 'your_api_key_here'
}

files = {
    'image': open('/path/to/image.jpg', 'rb')
}

response = requests.post('https://api.apiverve.com/v1/imagecaption', headers=headers, files=files)

data = response.json()
print(data)

package main

import (
    "bytes"
    "fmt"
    "io"
    "mime/multipart"
    "net/http"
    "os"
)

func main() {
    file, _ := os.Open("/path/to/image.jpg")
    defer file.Close()

    body := &bytes.Buffer{}
    writer := multipart.NewWriter(body)
    part, _ := writer.CreateFormFile("image", "image.jpg")
    io.Copy(part, file)
    writer.Close()

    req, _ := http.NewRequest("POST", "https://api.apiverve.com/v1/imagecaption", body)
    req.Header.Set("X-API-Key", "your_api_key_here")
    req.Header.Set("Content-Type", writer.FormDataContentType())

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    respBody, _ := io.ReadAll(resp.Body)
    fmt.Println(string(respBody))
}

{
  "status": "ok",
  "error": null,
  "data": {
    "caption": "A golden retriever running through a grassy field on a sunny day"
  }
}

Authentication

The Image Caption API requires authentication via API key. Include your API key in the request header:

X-API-Key: your_api_key_here

Learn more about authentication →

Interactive API Playground

Test the Image Caption API directly in your browser with live requests and responses.

File Upload Required

curl -X POST "https://api.apiverve.com/v1/imagecaption" \
  -H "X-API-Key: your_api_key_here" \
  -F "image=@/path/to/your/file"

const formData = new FormData();
formData.append('image', fileInput.files[0]);

const response = await fetch('https://api.apiverve.com/v1/imagecaption', {
  method: 'POST',
  headers: {
    'X-API-Key': 'your_api_key_here'
  },
  body: formData
});

const data = await response.json();
console.log(data);

Parameters

The following parameters are available for the Image Caption API:

Response

The Image Caption API returns responses in JSON, XML, YAML, and CSV formats. The JSON response is shown in the Example section above; alternative formats below.

Other Response Formats

<?xml version="1.0" encoding="UTF-8"?>
<response>
  <status>ok</status>
  <error xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>
  <data>
    <caption>A golden retriever running through a grassy field on a sunny day</caption>
  </data>
</response>

status: ok
error: null
data:
  caption: A golden retriever running through a grassy field on a sunny day

Response Structure

All API responses follow a consistent structure with the following fields:

Learn more about response formats →

Response Data Fields

When the request is successful, the data object contains the following fields:

Headers

Only X-API-Key is required. Optional headers include Accept for response format negotiation (JSON, XML, or YAML), User-Agent, and X-Request-ID for request tracing. See all request headers →

CORS Support

The Image Caption API accepts cross-origin requests from any origin, so it can be called directly from browser-based applications without a proxy. See CORS support →

Rate Limiting

Image Caption requests are throttled per minute on the Free plan and unthrottled on paid plans. Exceeding the limit returns 429 Too Many Requests; rate-limit usage is reported in the X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset response headers. See per-plan limits and best practices →

Error Codes

The Image Caption API uses standard HTTP status codes — 200 on success, 400 for invalid parameters, 401 for missing or invalid keys, 403 for insufficient credits, 429 for rate-limit exhaustion, and 500/503 for server-side issues. Each error response includes an X-Request-ID header you can quote when contacting support. See full error handling guide →

SDKs for Image Caption

Official Image Caption packages on npm, PyPI, NuGet, and JitPack — plus a Postman collection and an OpenAPI spec. See the SDK guide →

JitPack

No-Code Integrations

Image Caption works with Zapier, Make, Pipedream, n8n, and Power Automate using the same API key. See setup guides →

Zapier

Make

Pipedream

n8n

Power Automate

Frequently Asked Questions

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