WebP Conversion API Documentation

Simple, free API for converting WebP images to JPG or PNG

100 Free Conversions/DayNo API Key Required

Quick Start

Using cURL

curl -X POST \
  -F "file=@image.webp" \
  https://webp2jpg.co/api/convert?format=jpg \
  -o output.jpg

Using JavaScript/Node.js

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

const response = await fetch('https://webp2jpg.co/api/convert?format=jpg', {
  method: 'POST',
  body: formData
});

const blob = await response.blob();
const url = URL.createObjectURL(blob);
// Use the converted image

Using Python

import requests

with open('image.webp', 'rb') as f:
    files = {'file': f}
    response = requests.post(
        'https://webp2jpg.co/api/convert?format=jpg',
        files=files
    )

with open('output.jpg', 'wb') as f:
    f.write(response.content)

API Reference

POST/api/convert

Convert a WebP image to JPG or PNG format.

Request Parameters

Parameter	Type	Required	Description
file	multipart/form-data	Yes	WebP image file (max 10MB)
format	query string	No	Output format: `jpg` or `png` (default: jpg)
quality	query string	No	Quality 1-100 (default: 90)

Response

Success (200):

Returns converted image file as binary data
Content-Type: image/jpeg or image/png
Content-Disposition header includes suggested filename

Response Headers

Header	Description
X-Rate-Limit-Remaining	Remaining conversions today
X-Rate-Limit-Limit	Total daily limit (100)

Error Responses

429 Too Many Requests

{
  "error": "Rate limit exceeded",
  "message": "Free tier allows 100 conversions per day",
  "limit": 100
}

400 Bad Request

{
  "error": "No file provided"
}

413 Payload Too Large

{
  "error": "File too large",
  "message": "Maximum file size is 10MB",
  "maxSize": 10485760
}

Rate Limits

Free Tier

100 conversions per day
No API key required
Max 10MB per file
Rate limited by IP

Need More?

For higher volume needs, consider running your own instance or using our web interface.

Try Web Converter

Integration Examples

React Component

function WebPConverter() {
  const [converting, setConverting] = useState(false);

  const handleConvert = async (file) => {
    setConverting(true);

    const formData = new FormData();
    formData.append('file', file);

    const response = await fetch(
      'https://webp2jpg.co/api/convert?format=jpg',
      { method: 'POST', body: formData }
    );

    const blob = await response.blob();
    const url = URL.createObjectURL(blob);

    // Download or display converted image
    const a = document.createElement('a');
    a.href = url;
    a.download = 'converted.jpg';
    a.click();

    setConverting(false);
  };

  return (
    <input
      type="file"
      accept=".webp"
      onChange={(e) => handleConvert(e.target.files[0])}
      disabled={converting}
    />
  );
}

PHP

<?php
$file = $_FILES['image'];
$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, 'https://webp2jpg.co/api/convert?format=jpg');
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, [
    'file' => new CURLFile($file['tmp_name'], $file['type'], $file['name'])
]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$result = curl_exec($ch);
curl_close($ch);

header('Content-Type: image/jpeg');
echo $result;
?>

Best Practices

Check rate limit headers
Monitor X-Rate-Limit-Remaining to avoid hitting limits
Validate file types
Check file extension before uploading to save quota
Handle errors gracefully
Implement retry logic with exponential backoff
Compress before uploading
Stay under 10MB limit by resizing large images