Spreadsheet Converter

Excel to CSV Converter Free

Convert Excel XLSX and XLS files to CSV format online for free. Upload your spreadsheet, choose a sheet, set your delimiter, preview the data, and download a clean CSV file. All processing happens in your browser — data never leaves your device.

XLSX & XLS support Runs in browser Data never uploaded Data preview

Drop your Excel file here

XLSX · XLS · ODS

Pro — batch XLSX-to-CSV, merge multiple sheets, scheduled exports, API access

API access · Priority queue · Team workspace

Upgrade — $19/mo

How It Works

STEP 1

Upload Excel File

Drag and drop your .xlsx or .xls file onto the upload zone, or click Choose Excel File to browse. The SheetJS library reads the binary spreadsheet format entirely in your browser — no file is sent to any server. Excel files of any size are loaded instantly from your local disk.

STEP 2

Select Sheet & Preview

Multi-sheet workbooks are fully supported — use the Sheet dropdown to select which sheet to export. Choose your delimiter (comma, semicolon, tab, or pipe) and click Preview to see the first 10 rows in a formatted table. Verify column alignment before committing to the download.

STEP 3

Download CSV

Click Download CSV to generate and save the comma-separated file. The filename matches your original Excel file. All values containing the delimiter or line breaks are automatically quoted per RFC 4180. The result is compatible with every tool that reads standard CSV.

Excel to CSV Features

Professional XLSX parsing with real multi-sheet support

XLSX & XLS Support

Handles modern .xlsx (Office Open XML) and legacy .xls (BIFF8) formats using SheetJS, the most widely-used JavaScript spreadsheet library. Also supports .ods (OpenDocument Spreadsheet) from LibreOffice and Google Sheets exports. All file formats are parsed entirely in your browser without a server.

Multi-Sheet Selection

Workbooks with multiple sheets are fully supported. After uploading, the Sheet dropdown is populated with all sheet names from the workbook. Select the sheet you want to export and preview the data before downloading. This makes it easy to extract specific sheets from complex multi-tab Excel reports.

Flexible Delimiters

Export as comma-separated (standard CSV), semicolon-separated (European format compatible with Excel regional settings), tab-separated (TSV, used by databases and BI tools), or pipe-separated (used by SQL exports and data warehouses). Choose the delimiter expected by your downstream tool.

RFC 4180 Quoting

Fields containing the delimiter character, double-quote characters, or newlines are automatically wrapped in double-quotes per RFC 4180. Embedded double-quotes are escaped by doubling them. Use "Quote all fields" to wrap every value in quotes regardless of content — some legacy systems require this for reliable parsing.

Data Preview Table

Before downloading, preview the first 10 rows of data in a styled HTML table. Headers are highlighted in orange. The stats bar shows column count and total row count to confirm the data was read correctly. This prevents surprises — you can verify formulas were evaluated, dates were read correctly, and columns align as expected.

100% Private

SheetJS reads your Excel file entirely in the browser — no data is transmitted to any server at any point. Safe for confidential financial models, HR spreadsheets, medical records in Excel, customer data exports, and any proprietary spreadsheet data that must not leave your device or network.

Free vs Pro

FeatureFreePro
File size limit50 MB500 MB
Multi-sheet workbooks
Batch XLSX conversion
Export all sheets at once
Scheduled auto-export
REST API access

Frequently Asked Questions

Computed values are exported, not formula text. SheetJS reads the cached formula result stored in the Excel file — the same value you see in the cell when you open it in Excel. This means SUM, VLOOKUP, IF, and other formulas are all resolved to their current values in the CSV output. Note: if the Excel file was last saved with outdated cached values, those outdated values will be exported.

Excel dates are stored internally as serial numbers (days since January 1, 1900). SheetJS converts them to formatted date strings matching the cell's number format in the workbook. If no format is specified, ISO 8601 format (YYYY-MM-DD) is used as a safe universal default that is unambiguous regardless of locale.

No. SheetJS parses your Excel file entirely in your browser using the FileReader API. No data is uploaded, transmitted, or stored anywhere. This makes it safe to convert confidential financial spreadsheets, HR data, customer lists, medical records in Excel, and any other sensitive data that must not leave your device.

Use comma for most tools (Python pandas, databases, Google Sheets, standard CSV importers). Use semicolon if your target is Excel with a European locale (where Excel expects semicolons because commas are used as decimal separators). Use tab for database imports, BI tools like Tableau, and legacy mainframe systems. Use pipe for SQL exports and systems where data may contain commas or semicolons.