Skip to main content
MyDataFixer

CSV to Excel Converter

Turn a CSV file into an Excel workbook. Clear numbers and dates become real Excel values; codes with leading zeros, long IDs and anything ambiguous stay exactly as written.

Open a CSV file to turn it into an Excel workbook. Everything happens on your device: the file is not uploaded and is never changed.

Your file is read by your browser on this device. It is not uploaded to our servers.

How the CSV to Excel converter works

  1. Open a CSV, TSV or TXT file. The separator and text encoding are detected and can be changed.
  2. A quick structure check runs first. If the file has problems, “Check and repair in the CSV Validator” opens the same file there.
  3. Choose whether the first row contains column names. If it does, the new workbook gets a bold header row, frozen at the top, with a filter.
  4. Convert. Clear numbers and year-month-day dates become real Excel values; everything else stays text exactly as written.
  5. The new workbook is checked cell by cell before it is downloaded, and the summary shows how many cells became numbers, dates and text.

Example

A customer list has ids such as 00002, phone numbers such as 07700900001, ZIP codes such as 00037, joining dates such as 2024-03-15 and balances such as 12.50. In the new workbook, the ids, phones and ZIP codes keep their leading zeros as text, the dates are real Excel dates, and the balances are numbers that still show two decimals. Dates written 05/05/2024 stay text, because they could be day-first or month-first.

What the converter never does

  • Upload your file or change it.
  • Drop leading zeros, round long numbers or guess date orders: those values stay text exactly as written.
  • Turn a value into a formula: =1+1 stays the text “=1+1”.
  • Leave rows out: more rows than one Excel sheet holds (1,048,576) continue on another sheet, with the column names repeated.

Good to know

  • Only year-month-day dates (2024-03-15) become dates. Dates with times, other date layouts and formatted numbers such as 1,250 or 12% stay text.
  • A value longer than 32,767 characters, or a row with more than 16,384 values, can't be stored in Excel; the conversion is refused with the reason instead of cutting data off.
  • Very large files need a computer or a recent phone with enough memory.

Questions and answers

Is my file uploaded?

No. Your browser opens the file on your device and every check, fix and download happens there. The contents of your file are not sent to MyDataFixer's servers or to anyone else, and your original file is never changed.

Why do some numbers stay as text?

To keep them exactly as written. Leading zeros (codes, phone numbers, ZIP codes) would be lost, numbers longer than 15 digits would be rounded, and values such as 1,250 or 12% can mean different things. The summary lists how many values were kept as text and why.

Which dates become real Excel dates?

Dates written year-month-day, such as 2024-03-15. A date such as 03/04/2024 stays text, because it could mean 3 April or March 4.

What happens with more than a million rows?

An Excel sheet holds at most 1,048,576 rows. Longer files continue on a second sheet (and a third if needed), each starting with the column names, and the summary says so.

Can I repair the file first?

Yes. If the structure check finds problems, “Check and repair in the CSV Validator” opens the same file there. Download the repaired CSV, then convert it.

Will the header row be formatted?

Yes, when “First row contains column names” is ticked: the header is bold, frozen at the top and has a filter. Untick it if the first row is data.

Related tools