CSV to Excel Converter
Paste CSV and download a proper Excel workbook where numbers are numbers and dates are dates.
Processed locally in your browser/ Your data stays in your browser.
What is CSV to Excel Converter?
Opening a CSV directly in Excel often mangles it: wrong delimiter, IDs turned into numbers, dates reinterpreted by the local settings. Creating an .xlsx file yourself gives you typed cells and a predictable result.
The converter parses the CSV with a real parser, then builds a workbook with SheetJS. It can convert plain numbers, true/false and ISO dates (2025-03-01 or 2025-03-01 14:30) into typed cells, while text with leading zeros or more than 15 digits stays text. It also names the sheet, sizes columns to fit and adds filter arrows on the header row.
How does it work?
- Paste your CSV or open a .csv file. The delimiter is detected automatically unless you set it.
- Set the sheet name and choose whether the first row is a header.
- Keep or turn off the conversion of numbers, booleans and ISO dates.
- Click Create .xlsx file, check the preview and download data.xlsx.
Common use cases
- Sending a report to colleagues who expect an Excel file rather than a CSV.
- Preserving codes such as 00123 that Excel would otherwise turn into 123.
- Getting real Excel dates from ISO timestamps produced by a script or database.
- Creating a starter workbook from an export before adding formulas by hand.
Examples
Try this input in the tool above:
id,product,price,in_stock,added 1,Notebook,4.5,true,2025-03-01 2,Pen,1.2,false,2025-03-02 3,"Desk, oak",219,true,2025-03-05
id | product | price | in_stock | added 1 | Notebook | 4.5 | true | 2025-03-01 2 | Pen | 1.2 | false | 2025-03-02 3 | Desk, oak | 219 | true | 2025-03-05
Privacy
CSV to Excel Converter runs entirely in your browser. The text or files you provide are processed on your device and are not uploaded, logged or stored on our servers.
Limitations
The workbook contains values only: no formulas, styling or multiple sheets. Excel sheets are limited to 1,048,576 rows and 16,384 columns. Only ISO-style dates are recognized.
Frequently asked questions
Why are some numbers stored as text?
Values with leading zeros (00123) and numbers longer than 15 digits are kept as text because Excel would otherwise lose leading zeros or round digits. Turn conversion off to store every cell as text.
Which date formats become real dates?
ISO dates such as 2025-03-01 and date-times such as 2025-03-01 14:30 or 2025-03-01T14:30:00. Other formats stay as text to avoid day/month mix-ups.
Is the file sent to a server?
No. The .xlsx file is generated in your browser and only offered to you as a download.
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