The short answer
Load the CSV, check that the delimiter was detected correctly, tell the converter whether the first row is a header, keep ID-like columns as text and download the .xlsx. The result is a real Excel workbook with numbers stored as numbers and a bold, frozen header row.
Step by step
- Choose a CSV file or paste CSV text into the CSV to Excel tool.
- Check the delimiter. Comma, semicolon, tab and pipe are detected automatically, and you can pick one by hand.
- Tick whether the first row is a header.
- Look at the preview of the first rows to confirm the columns line up.
- Tick “treat all cells as text” if nothing should be converted to numbers.
- Download the .xlsx.
Why CSVs open wrongly in Excel
| Symptom | Cause | Fix |
|---|---|---|
| Everything is in column A | Wrong delimiter for your regional settings | Choose the right delimiter when converting |
| ZIP or PIN code lost its leading zero | Excel treated the column as a number | Keep that column as text |
| Long ID shows as 1.23E+15 | Very long digits shown in scientific notation | Keep as text |
| Accents appear as strange characters | The file is UTF-8 but was read in another encoding | Import using UTF-8, or convert in the browser |
| Dates are swapped (day and month) | Regional date order | Check the preview before relying on dates |
CSV or XLSX: which should you keep?
CSV is plain text. It is small, readable by any program and ideal for moving data between systems, but it has no formatting, no multiple sheets and no types. XLSX stores types, header formatting and more. Use CSV to exchange data and XLSX to work with it by hand.
Private by default
The workbook is built in your browser and the file never leaves your device.
Frequently asked questions
How do I convert CSV to Excel?
Open the CSV in a converter, check the delimiter, mark the header row and download an .xlsx file.
How do I keep leading zeros when opening a CSV in Excel?
Keep the column as text. In the CSV to Excel tool, tick “treat all cells as text”, or the converter keeps leading-zero and very long codes as text automatically.
Why does my CSV open in one column?
The delimiter does not match what Excel expects. Choose comma, semicolon, tab or pipe to match the file.
Is a CSV the same as an Excel file?
No. CSV is plain text with separators. An .xlsx is a structured workbook with types and formatting.
Is my file uploaded?
No. The conversion happens in your browser.
Try these tools
CSV to Excel Converter
Convert a CSV file to a real Excel .xlsx online. Auto-detects the delimiter, keeps numbers and leading zeros, bold frozen header. Free, private, no upload.
Open toolExcel to CSV Converter
Convert .xlsx sheets to CSV in your browser. Preview rows, pick a sheet, set delimiter and BOM, or export all sheets as ZIP. Files stay on your device.
Open toolCSV Viewer
Open a CSV file and browse it as a sortable, searchable table with row counts and 100-row paging. Download the filtered rows. Private; nothing is uploaded.
Open toolJSON to CSV
Convert a JSON array to CSV in your browser. Flattens nested objects, picks delimiters and downloads a ready .csv for Excel or Sheets.
Open toolCSV Delimiter Converter
Convert between comma, semicolon, tab and pipe separated files. Auto-detects the delimiter, handles quoted fields, shows a preview. Free and private.
Open toolKeep reading
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Read guideHow to convert JSON to CSV, with a worked example
Turn a JSON array into a CSV you can open in Excel or Google Sheets. See how nested objects and arrays are flattened, with a worked example and common pitfalls.
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