Merge, split, compress, rotate, and modify PDFs with simple API calls to enhance your document processing workflows.
The Merge API allows you to combine multiple PDF files into a single PDF document. You can specify the order of the files, and the API handles large merges efficiently using a staged approach for more than 10 files.
POST https://mega-pdf.com/api/mergeAuthenticate requests using an API key in the x-api-key header or as a query parameter (api_key).
// Header example
x-api-key: your-api-key
// Query parameter example
https://mega-pdf.com/api/merge?api_key=your-api-key
The API accepts multipart/form-data requests with the following parameters:
| Parameter | Type | Description | Required |
|---|---|---|---|
files | File[] | Array of PDF files to merge (minimum 2 files) | Yes |
order | String (JSON array) | Array of indices specifying the merge order (e.g., [0, 1, 2]) | No |
Merge two PDFs using cURL:
curl -X POST https://mega-pdf.com/api/merge \
-H "x-api-key: your-api-key" \
-F "files=@/path/to/doc1.pdf" \
-F "files=@/path/to/doc2.pdf" \
-F "order=[0,1]"
Successful responses include the merged file URL and metadata:
{
"success": true,
"message": "PDF merge successful",
"fileUrl": "/api/file?folder=merges&filename=uuid-merged.pdf",
"filename": "uuid-merged.pdf",
"mergedSize": 1234567,
"totalInputSize": 2345678,
"fileCount": 2
}Error responses:
{
"success": false,
"error": "At least two PDF files are required for merging"
}Using the Merge API with JavaScript (Node.js):
const formData = new FormData();
formData.append('files', fs.createReadStream('doc1.pdf'));
formData.append('files', fs.createReadStream('doc2.pdf'));
formData.append('order', JSON.stringify([0, 1]));
fetch('https://mega-pdf.com/api/merge', {
method: 'POST',
headers: {
'x-api-key': 'your-api-key'
},
body: formData
})
.then(response => response.json())
.then(data => {
if (data.success) {
console.log('Merge successful:', data.fileUrl);
} else {
console.error('Merge failed:', data.error);
}
})
.catch(error => console.error('Error:', error));