CSV to Excel Converter Free
Convert CSV files to real Excel XLSX spreadsheets online for free. Upload a .csv file or paste CSV text directly. Auto-detects comma, semicolon, or tab delimiters. Data preview before download. No signup, works in your browser.
CSV Input
Drop your .csv file here
or click to browse
Data Preview
Showing up to 10 rows ·
Pro — multi-sheet XLSX, column type mapping, batch CSV merge, styled headers, API
API access · Priority queue · Team workspace
How It Works
Paste or Upload CSV
Paste CSV text directly into the editor or upload a .csv or .tsv file using the Upload tab. Drag-and-drop is supported. The tool reads the raw text in your browser — no file is transmitted over the network. You can use any CSV exported from a spreadsheet, database, reporting tool, or written by hand.
Preview the Data
Click Preview to see the first 10 rows of your data in a formatted table. The auto-detect engine analyses the first line to determine the delimiter automatically — comma, semicolon, tab, or pipe. You can override this using the Delimiter dropdown if your data uses an unusual separator. Verify column alignment before downloading.
Download XLSX
Click Download XLSX to generate and save a genuine Excel spreadsheet. SheetJS builds a real Office Open XML (.xlsx) file in your browser memory and triggers a file download — no server round-trip. The output opens natively in Microsoft Excel, Google Sheets, LibreOffice Calc, and Apple Numbers.
CSV to Excel Features
Professional spreadsheet conversion with real XLSX output
Real XLSX Output
Uses the SheetJS library to generate a genuine Office Open XML spreadsheet file. The output is not a renamed CSV — it is a proper .xlsx file with a workbook, worksheet, and correctly typed cell values. Opens natively in every major spreadsheet application without import dialogs or format warnings.
Smart Auto-Detect
The delimiter auto-detect engine analyses the frequency of comma, semicolon, tab, and pipe characters on the first line and picks the most likely separator. This correctly handles European CSV files (semicolon-delimited), TSV files, and pipe-delimited exports from databases without requiring manual configuration.
RFC 4180 Quoted Fields
Fields containing the delimiter, line breaks, or double-quote characters are supported when wrapped in double-quotes, per the RFC 4180 CSV standard. Escaped double-quotes ("") inside quoted fields are decoded correctly, so addresses, full names with commas, and multi-line text cells parse without errors.
Data Preview Table
Before downloading, preview up to 10 rows of parsed data in a formatted HTML table. Column headers (if present) are highlighted in purple. The stats bar shows total column count and full row count so you can verify the data was parsed correctly before generating the Excel file.
Number Auto-Convert
Enable "Auto-convert numbers" to store numeric cell values as Excel numbers rather than text strings. This means Excel formulas, SUM, AVERAGE, and sorting by number will work correctly on the converted data. Useful for CSV exports from databases, payment systems, and analytics tools where numeric columns arrive as quoted text.
Private — No Upload
All CSV parsing and XLSX generation happens entirely in your browser. Your spreadsheet data is never uploaded, transmitted, or stored. This makes it safe to convert confidential data: customer lists, financial reports, HR records, medical data, and any other sensitive information that must not leave your device.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| File size limit | 50 MB | 500 MB |
| Multi-sheet XLSX | — | |
| Styled header row | — | |
| Batch CSV merge | — | |
| Column type mapping | — | |
| REST API access | — |
Frequently Asked Questions
It is a genuine XLSX file generated using the SheetJS library in your browser. The output opens natively in Microsoft Excel, LibreOffice Calc, Google Sheets, Apple Numbers, and any application that reads the Office Open XML format. Columns, rows, and data types are all properly encoded — it is not a CSV file with a renamed extension.
Auto-detect mode analyses the first line of your CSV and picks the most likely delimiter from comma (,), semicolon (;), tab, and pipe (|). You can override auto-detect using the Delimiter dropdown. European CSV exports often use semicolons because commas are used as decimal separators — switch to semicolon if your data looks wrong in the preview.
Yes. RFC 4180 quoted fields are fully supported — fields wrapped in double-quotes that contain commas, newlines, or embedded quotes are parsed correctly. For example, "Smith, John","123 Main St, Apt 4" is parsed as two fields, not four.
No. The CSV parsing and XLSX generation both run entirely in your browser using the SheetJS library. No data is uploaded, transmitted, or stored anywhere. This makes it safe to use with confidential spreadsheet data, customer records, financial data, and HR information.