Free CSV to Excel converter
Opening a CSV straight in Excel drops leading zeros, rounds long IDs, and guesses at dates. Convert it here instead: plain numbers stay numbers, everything else stays exactly as written, and the header row is bold and frozen.
Runs in your browser. Your file is never uploaded.
You can also drop a file anywhere on this page. Up to 50 MB.
Result
Paste CSV or choose a file, and the sheet preview appears here.
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How it works
- 1
Paste CSV or choose a file
Comma, semicolon, tab, and pipe separators are detected for you, and files saved by Excel on Windows are read correctly.
- 2
Check the result
It says how many values became numbers and dates, and how many look like numbers but stay text.
- 3
Download the .xlsx file
The file is built in your browser when you click download, with one sheet named after your CSV.
- What becomes a number
- Plain numbers like 42, -7, and 1250.50. Values with a thousands separator or currency sign stay text, and so does any column with a leading zero or an ID longer than 15 digits, so ZIP codes stay consistent all the way down.
- What becomes a date
- ISO dates like 2026-10-06, with or without a time. Dates like 10/06/2026 stay text, because they mean different days in the US and elsewhere.
- Formulas
- Values that start with = are stored as text, so nothing in a CSV can run as a formula when the file opens.
Questions
Why not just open the CSV in Excel?
Excel converts values as it opens a CSV. ZIP codes like 02134 lose their leading zero, IDs longer than 15 digits are rounded, and some text turns into dates. An .xlsx file stores each value with its type, so nothing gets converted when it opens.
Can I turn several CSV files into one workbook?
Not yet. Each CSV becomes a workbook with one sheet. If you combine the same files every week, that's a good job to automate.
How big a file can it handle?
Up to 50 MB. Most computers handle that in a few seconds. If you convert files that size on a regular schedule, a small automated job is usually the better fit.
Is my file uploaded anywhere?
No. The conversion runs in your browser with the JavaScript on this page. Your data never leaves your computer, and nothing is kept after you close the tab.
Rebuilding the same spreadsheet every week?
I set up reports that pull data from your systems straight into a spreadsheet or dashboard, so nobody has to export and reformat it by hand.
