Free Excel Converter Online - XLSX to CSV, CSV to Excel
CSV to Excel Converter
Convert CSV files to Excel spreadsheets (XLSX) instantly in your browser. Auto-detect delimiters, format columns. No uploads, works offline.
Csv To Xlsx
Convert CSV files to Excel spreadsheets (XLSX) instantly in your browser. Auto-detects delimiters, preserves data formatting. Private, no uploads.
Csv To Ods
Convert CSV files to OpenDocument Spreadsheet (ODS) format for LibreOffice and OpenOffice. Auto-detect delimiters. No uploads required.
Csv To Tsv
Convert CSV files to TSV (tab-separated values) format. Change delimiter from comma to tab. No uploads, all processing in browser.
Excel To Csv
Convert Excel spreadsheets (XLSX, XLS) to CSV format instantly in your browser. Select sheets, customize delimiters. No uploads, works offline.
Xlsx To Html
Convert Excel (XLSX, XLS) to HTML tables for web embedding. Add Bootstrap styling, responsive tables, clean markup. Works offline, no uploads.
Xlsx To Json
Convert Excel spreadsheets (XLSX, XLS) to JSON format instantly. Select sheets, customize output format, preview data. No uploads, works offline.
Xlsx To Markdown
Convert Excel spreadsheets to Markdown tables. Select sheets, format columns, copy or download. No uploads, works offline.
Json To Xlsx
Convert JSON to Excel spreadsheet (XLSX) in your browser. Handles nested objects and arrays with flattening options. Free, private, no uploads required.
Ods To Csv
Convert OpenDocument Spreadsheet (ODS) files to CSV format instantly in your browser. Select sheets, customize delimiters. No uploads required.
Ods To Xlsx
Convert OpenDocument Spreadsheet (ODS) files to Microsoft Excel XLSX format. Preserve data, sheets, formatting. No uploads, works in browser.
Tsv To Csv
Convert TSV files to CSV (comma-separated values) format. Change delimiter from tab to comma. No uploads, all processing in browser.
Xlsx To Ods
Convert Microsoft Excel spreadsheets (XLSX) to OpenDocument Spreadsheet (ODS) format for LibreOffice. No uploads, works in browser.
Spreadsheet Format Conversion
Spreadsheet conversion enables data exchange between different office suites and systems. Whether you're migrating from Excel to Google Sheets, importing data into a database, or sharing files with users on different platforms, format conversion bridges compatibility gaps.
Excel Formats (XLSX, XLS)
XLSX is Microsoft Excel's modern format, introduced in Office 2007. It's an XML-based format stored in a ZIP container, supporting multiple sheets, formulas, charts, formatting, and pivot tables. XLSX files are smaller than legacy XLS and are widely supported.
XLS is the legacy binary format from earlier Excel versions. While still readable by modern software, it has size limitations (65,536 rows) and lacks newer features.
OpenDocument Spreadsheet (ODS)
ODS is the open standard used by LibreOffice Calc, OpenOffice, and Google Sheets (for export). As an ISO-standardized format, it ensures long-term accessibility and vendor independence. ODS supports most features found in XLSX.
CSV for Data Exchange
CSV is the universal exchange format for tabular data. It exports a single sheet as plain text with comma-separated values. While CSV loses formatting, formulas, and multiple sheets, it's readable by virtually any software including databases, programming languages, and text editors.
Conversion Scenarios
- Excel to CSV: Export data for database import or data analysis tools
- CSV to Excel: Add formatting, formulas, and charts to raw data
- XLSX to ODS: Share files with LibreOffice users or migrate away from Microsoft Office
- Multi-sheet export: Convert workbooks to multiple CSV files or ZIP archives
Preserving Data Integrity
Our converters handle special cases that often cause problems: dates in various formats, numbers stored as text, Unicode characters, and cells with leading zeros. Preview your conversion before downloading to ensure data integrity.