CSV to Excel Converter
Upload or paste CSV files and download a proper .xlsx file — with type detection, multiple sheets, and no server upload needed.
🔒 100% private — runs in your browser, no data sent to servers
CSV Input
Sheets
Preview
Paste CSV text or upload a file above to see a preview here.
Showing first 100 rows — all rows will be included in the .xlsx download
Related Tools
All processing is performed entirely in your browser using SheetJS. Your CSV data is never uploaded to any server. Large files may impact browser performance depending on available memory.
Frequently Asked Questions
No. This converter is 100% client-side and uses SheetJS running entirely in your browser. Your CSV data never leaves your device and is never sent to any server. You can even use it offline once the page has loaded.
There is no hard limit imposed by the tool — it is constrained only by your browser’s available memory. Files up to 50MB work fine in most modern browsers. Very large files (100MB+) may cause slowdowns depending on your device.
The tool examines the first line of your CSV and counts the occurrences of commas, tabs, semicolons, and pipes. The character that appears most frequently is selected as the delimiter. You can always override this manually using the Delimiter dropdown.
Yes. After loading your first CSV, click the “Add Sheet” button to add additional sheets. Each sheet can have its own name, CSV source, and settings. All sheets are exported together into a single .xlsx file when you click “Download .xlsx”.
When type detection is enabled, the converter recognises integers and decimals (e.g. 42, 3.14), ISO 8601 dates (e.g. 2024-01-15 or 2024-01-15T09:00), and US-style dates (e.g. 01/15/2024). These are stored as native Excel number or date cells rather than plain text strings, so you can sort, filter, and calculate with them in Excel.