Convert XLS to CSV — Free Online Converter
Convert Microsoft Excel Spreadsheet (.xls) to Comma-Separated Values (.csv) online for free. Fast, secure document conversion with no watermarks or registration.
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How to Convert
Upload your .xls file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .csv file when it's ready.
About XLS to CSV Conversion
XLS is Microsoft's legacy binary spreadsheet format, used by Excel 97 through Excel 2003 and encoded in the Binary Interchange File Format (BIFF). CSV (Comma-Separated Values) is a plain-text tabular format where each row is a line and columns are separated by commas. Converting XLS to CSV extracts the cell data from the binary container and outputs it as a universally readable text file that any programming language, database import tool, or spreadsheet application can parse.
This conversion strips away all formatting, formulas, charts, macros, and multiple-sheet structure that the XLS file may contain. Only raw cell values from the active or first worksheet are exported, producing a lightweight text file that is ideal for data interchange, database imports, and automated processing pipelines.
Why Convert XLS to CSV?
CSV is the universal exchange format for tabular data. Every database system, scripting language, ETL pipeline, and analytics platform can ingest CSV natively. When you need to feed XLS spreadsheet data into Python pandas, R, SQL Server bulk import, or a cloud data warehouse like BigQuery or Snowflake, CSV is the expected input format.
Legacy XLS files locked in the BIFF binary format cannot be read by many modern data tools without specialized libraries. Converting to CSV removes the Microsoft-specific encoding and produces a standards-based text file that will remain readable for decades without any proprietary software dependency.
Common Use Cases
- Import legacy Excel 97-2003 spreadsheet data into SQL databases
- Feed XLS financial records into Python or R analytics scripts
- Prepare XLS inventory lists for bulk upload to e-commerce platforms
- Convert XLS contact lists for CRM system imports
- Extract XLS survey data for processing in statistical software
How It Works
The conversion engine uses LibreOffice in headless mode to open the XLS binary file, interpret the BIFF record stream, and export the first worksheet as CSV with UTF-8 encoding and comma delimiters. Formulas are resolved to their computed values at the time of conversion. Dates are exported in ISO 8601 format. Numeric precision is preserved up to 15 significant digits, matching Excel's internal double-precision floating-point representation.
Quality & Performance
Cell values are exported with full numeric precision. Formatting such as currency symbols, percentage signs, and thousands separators is stripped — only raw values remain. Merged cells are unmerged, with the value placed in the top-left cell and remaining cells left empty. Multi-sheet workbooks export only the first sheet; convert each sheet separately if all sheets are needed.
Device Compatibility
| Device | XLS | CSV |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No |
Tips for Best Results
- 1Check that formulas have been recalculated in Excel before converting — stale formula results carry over
- 2Convert multi-sheet workbooks one sheet at a time for complete data extraction
- 3Verify date formats in the output match your target system's expectations
- 4Use a text editor to inspect the first few lines of the CSV before bulk importing into a database
- 5Remove header rows or adjust column names in the CSV if the target system expects specific field names
Related Conversions
XLS to CSV conversion liberates spreadsheet data from Microsoft's proprietary binary format into a universal plain-text representation suitable for any data processing workflow.