How to use it
- Paste CSV data or open a .csv, .tsv or .txt file.
- Leave the delimiter on automatic detection or choose it.
- Choose whether the first row is a header and whether numbers should be stored as numbers.
- Select Convert and download .xlsx.
How it works
The CSV is read with a standard (RFC 4180) parser: fields may be quoted, quoted fields may contain the delimiter and line breaks, and doubled quotes stand for one quote. Automatic detection tries comma, semicolon, tab and pipe and picks the one that splits the first rows into the most consistent number of columns. A byte order mark at the start is ignored.
The workbook has one sheet. With a header row, the first row is bold, stays visible while you scroll and gets filter buttons. Column widths follow the longest value in each column (limited to a sensible maximum).
With Store numbers as numbers, only plain decimal numbers (42, -3.5, 1e6) become numeric cells. Numbers with leading zeros, thousands separators, decimal commas or more than 15 significant digits stay text, because converting them would change them. Text that starts with = is stored as text, never as a formula. Dates are kept as text exactly as written.
Examples
Export from a web shop
An order export separated by semicolons opens as one column in Excel. Converting it here detects the semicolons and gives one column per field with a frozen header.
Keeping product codes intact
Codes such as 00451 stay text, so the leading zeros are not lost the way they are when Excel opens the CSV directly.
Frequently asked questions
Why do some numbers stay text?
Values with leading zeros, decimal commas, thousands separators or more than 15 digits stay text so they are not changed. Turn off Store numbers as numbers to keep every cell as text.
Are dates converted to Excel dates?
No. Date formats in CSV files differ by country, so dates are kept as text exactly as written. You can convert them in Excel with Text to Columns or DATEVALUE.
What encoding should my CSV file have?
Files are read as UTF-8. If special characters look wrong, the file was saved in an older encoding; open it in a text editor and save it as UTF-8 first.
Is there a size limit?
Files you open are limited by your plan's file size limit. Very large CSVs also need enough memory in your browser, because the whole workbook is built on your device.
Privacy
The CSV data is converted in your browser and the .xlsx file is created on your device. Nothing is uploaded, stored or included in analytics; only an anonymous event that the tool was used is counted.