Know your formats
Supported formats and limitations
- Input formats
- CSV
- Output formats
- XLSX
- All values are stored as text, including numbers, dates, leading zeros and formula-like strings.
- Limits include 25,000 rows, 256 columns and 250,000 cells.
The parser reads UTF-8 comma-separated records with quoted commas and line breaks. The workbook contains one Data worksheet, including the header row if present. All cells are text, so 001 keeps its leading zeros and =1+2 stays literal. Numeric calculations require explicit conversion in your spreadsheet application.
Maximum input size is 2 MiB per file.
A local workflow
How to use this converter
Your file contents stay in the browser as you work.
Select the CSV with its header row if it has one.
Convert the rows into the Data worksheet.
Download and open the XLSX workbook.
A little more clarity
Frequently asked questions
What happens to a field beginning with an equals sign?
The workbook stores it as a string, so the spreadsheet can display the original text without evaluating it as a formula.
Is CSV to XLSX available now?
This tool runs locally with JavaScript enabled. Check its supported formats and size limits before converting.