Convert CSV to XLSX Free Online — Import Data into Excel

Convert CSV data files to Excel XLSX format with automatic column detection and data type preservation. Free online converter.

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CSV vs XLSX: Side-by-side

Technical comparison of the two formats — useful for deciding which to use, or for confirming what changes during conversion.

Property	CSV	XLSX
Full name	Comma-Separated Values	Microsoft Excel (Open XML)
Year introduced	1972	2007
Developer / standard body	IBM (informal)	Microsoft
MIME type	text/csv	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
File extension	.csv	.xlsx
Compression	None	ZIP-compressed XML
Color / data depth	N/A	N/A
Max dimensions / size	Unlimited	1,048,576 rows × 16,384 columns
Transparency	No	No
Animation	No	No
Standard / specification	IETF RFC 4180	ECMA-376 / ISO/IEC 29500
Best for	Data interchange, database imports, ETL pipelines	Modern Excel spreadsheets, data analysis

About the CSV Format

CSV (Comma-Separated Values) is a plain text format that stores tabular data with each row on a new line and values separated by commas. CSV has no formal standard body, though RFC 4180 defines common conventions. Its simplicity makes CSV the most universally supported data interchange format — every spreadsheet, database, programming language, and analytics tool can read and write CSV files.

CSV files contain only raw data values with no formatting, formulas, charts, or metadata. This simplicity is both its strength and limitation: CSV files are compact, human-readable in any text editor, and import seamlessly into databases and data processing pipelines. CSV is the standard format for data exports, ETL workflows, machine learning datasets, CRM imports, and moving data between incompatible systems.

CSV to XLSX FAQ

Quick answers about compatibility, quality, metadata handling, and the most common reasons to convert CSV files to XLSX.

How do I convert a CSV file to Excel XLSX?

Upload your CSV file and click Convert. iFormat converts the comma-separated data into an Excel XLSX spreadsheet with proper cells, rows, and columns. Download instantly — no Excel or Google Sheets required.

Why convert CSV to XLSX?

CSV is plain text with limited formatting. Converting to XLSX lets you open the data in Excel or Google Sheets with proper column formatting, apply formulas, create charts, sort and filter data, and use all spreadsheet features.

Will all my data columns be preserved?

Yes. All columns and rows from the CSV are mapped to the corresponding cells in the XLSX. Column headers (if present in the first row) are preserved. Data types like numbers, dates, and text are automatically detected.

What is a CSV file?

CSV (Comma-Separated Values) is a simple plain-text format where each row is a line and columns are separated by commas. It's the universal data exchange format for spreadsheets, databases, and data analysis tools.

Is CSV to XLSX conversion free?

Yes — completely free with no watermarks. CSV files are usually small, well within the free plan's 50 MB limit.