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HomeUtilityXLSX to CSV

XLSX to CSV Converter

Convert Excel spreadsheets to CSV with sheet selection and preview. Free, private, runs in your browser.

100% private — your files never leave your browser. All processing happens locally on your device.

Drop an XLSX or XLS file here, or click to browse

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What Is XLSX to CSV Conversion?

XLSX is Microsoft Excel's modern spreadsheet format, containing multiple sheets, formulas, formatting, charts, and embedded objects. CSV (Comma-Separated Values) is a plain-text format that stores tabular data as rows of comma-delimited values. Converting XLSX to CSV extracts the raw data from a spreadsheet into a universal format that can be imported into databases, data analysis tools, programming languages, and any application that processes tabular data.

Why Convert XLSX to CSV?

CSV is the lingua franca of data. While Excel files are great for human viewing and editing, many systems require CSV for data import — databases (MySQL, PostgreSQL), programming languages (Python pandas, R), data pipelines (ETL tools), machine learning frameworks, and API integrations. CSV files are also significantly smaller than XLSX files since they contain only raw data without formatting, formulas, or metadata. Converting to CSV ensures maximum compatibility across tools and platforms.

How Does This Converter Work?

The tool uses SheetJS, the most widely-used JavaScript spreadsheet parser, to read your XLSX or XLS file entirely in the browser. It extracts the data from each sheet, resolves formulas to their calculated values, and generates clean CSV output. For multi-sheet workbooks, a dropdown lets you select which sheet to convert, or download all sheets as separate CSV files. You can configure the delimiter (comma, tab, semicolon, pipe) and preview the data in a table before downloading.

Is It Safe?

Completely. Your spreadsheet is parsed entirely in your browser — no file upload, no server processing, no cloud storage. Spreadsheets often contain sensitive business data, financial records, or personal information. With Convertful, that data never leaves your device.

FAQ

What Excel formats are supported?

Both .xlsx (modern) and .xls (legacy) formats are supported. The tool uses SheetJS to parse all common spreadsheet formats.

How are multi-sheet workbooks handled?

A sheet selector dropdown lets you choose which sheet to convert. You can also download all sheets as separate CSV files.

Are formulas preserved?

Formula cells are exported with their calculated values, not the formula strings. The CSV contains the final computed data.

Is my data safe?

Yes. Your spreadsheet is parsed entirely in your browser using JavaScript. No files are uploaded to any server.