How to Convert CSV to XLSX

Step‑by‑step guide to using Sheetize for transforming CSV files into XLSX workbooks (macro‑free), ideal for reporting, data analysis and sharing.

Sheetize CSV‑to‑XLSX Converter for .NET

Sheetize provides a simple yet powerful API for reading CSV data and writing it to an Excel workbook while preserving column types, header rows and cell styling. It’s handy when you need to distribute data in a familiar spreadsheet format or integrate it into workflows that only accept XLSX files.

Main Features

Convert CSV to XLSX

Read any CSV (comma, semicolon, tab‑delimited) and generate a macro‑free XLSX file, with optional data‑type inference and custom column formatting.

Preserve Formatting & Data Types

Detect numbers, dates, booleans and apply appropriate Excel styles; you can also supply a style template to keep a consistent look.

Streaming Support

Process huge CSV files row‑by‑row to keep memory usage low – perfect for batch conversions or web services.

Detailed Instructions

CSV → XLSX Workflow

To convert a CSV file to XLSX with Sheetize, follow these steps:

  1. Initialise the Converter – create an instance of TextConverter.
  2. Configure Options – set LoadOptions (delimiter, encoding, hasHeader) and TextConverterSaveOptions (output path, style template).
  3. Define File Paths – provide the source CSV path and the destination XLSX location.
  4. Execute Conversion – call Process with the prepared options.

Example – Convert a CSV to XLSX 

using Sheetize;

var readOptions = new LoadOptions
{
    InputFile = "sales_data.csv"
};

var saveOptions = new TextConverterSaveOptions
{
    OutputFile = @"E:\reports\sales_report.xlsx"
};

TextConverter.Process(readOptions, saveOptions);

Expanded Format Support

  • Sheetize can also convert XLSX back to CSV, optionally selecting specific sheets or ranges.
  • The library supports exporting to JSON, TSV or HTML directly from the generated workbook, enabling end‑to‑end reporting pipelines (e.g. CSV → XLSX → HTML).

With these capabilities, Sheetize makes CSV‑to‑XLSX conversion effortless, whether you need a quick one‑off script or a production‑grade service.

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