CSV to Excel, CSV to XLSX, Spreadsheet API

Convert CSV Files to Excel XLSX via API

Convert CSV files to Microsoft Excel XLSX spreadsheets via REST API. Upload your CSV file as multipart/form-data and receive a formatted Excel workbook in response. Perfect for report generation and data export pipelines.

cURLPythonNode.jsn8n
# Convert CSV file to Excel XLSX
curl -X POST \
  https://api.convertfilefast.com/v2/convert/csv-to-xlsx \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "file=@data.csv" \
  --output output.xlsx

# HTTP 200 OK — Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Conversion completed in <2s

Advantages

Why use our API?

Complete and reliable solution for integration in any tech stack.

Excel-Ready Output

Receive a properly formatted XLSX file that opens directly in Microsoft Excel, Google Sheets, and LibreOffice Calc.

Simple Upload

Upload your CSV as multipart/form-data and receive the Excel XLSX binary in response. No configuration needed.

Column Formatting

CSV columns are mapped to Excel cells with automatic column width adjustment and header formatting.

Report Generation

Use in report generation pipelines to deliver data as Excel files to clients, stakeholders, and dashboards.

n8n & Automation

Convert CSV exports from databases or APIs to Excel in n8n workflows and send via email or save to Drive.

Zero Storage

CSV files are converted in memory and deleted immediately. Your data is never stored on our servers.

Start Converting CSV to Excel

Get your API key and convert CSV files to Excel XLSX in seconds. Free plan includes 10 conversions per month.

No credit card. 10 free conversions on Free plan.