Convert CSV to Excel
Turn CSV and TSV files into real Excel workbooks with a bold, frozen header row, filters and fitted columns. Leading zeros, long ID numbers and special characters stay intact. It also converts Excel files back to CSV. Nothing is uploaded.
Free · No sign-up
How to use it
- Choose CSV to Excel, then select one or more CSV files, drop them on the box, or paste data copied from another program.
- The delimiter and character encoding are detected automatically. Check the preview and change them if the columns or letters look wrong.
- Choose how the data is stored: header row, numbers, leading zeros and dates. The defaults suit most files.
- Download the Excel file. Several CSV files become several sheets in one workbook.
- To go the other way, choose Excel to CSV, open an XLSX file, pick a sheet and download it as CSV.
Why use this tool
Leading zeros and long numbers kept
ZIP codes like 01234, phone numbers and 16-digit IDs stay exactly as they are, instead of being cut or turned into 1.23E+15.
No garbled characters
UTF-8 and older encodings such as Windows-1252, Shift_JIS or GBK are detected, so accents, Cyrillic, Chinese and Japanese text come out right.
Ready-to-use workbook
The header row is bold and frozen, has filter buttons, and the columns are sized to fit the data.
Several CSVs in one workbook
Select several CSV files at once and get one Excel file with a sheet for each, named after the files.
Excel to CSV too
Open an XLSX file, pick any sheet and save it as CSV with a comma, semicolon or tab, or download every sheet in a ZIP.
Private by design
Customer lists, sales data and other files are processed in your browser. Nothing is uploaded or stored.
Why not just open the CSV in Excel?
When Excel opens a CSV file directly, it guesses the type of every value. Leading zeros disappear from ZIP codes and product codes, numbers with more than 15 digits are rounded and shown as 1.23457E+15, and values like 3-4 can turn into dates. Text saved as UTF-8 can also appear as garbled characters such as é instead of é.
This converter makes those decisions carefully before Excel sees the data. Values that look like codes stay text, real numbers stay numbers, and the text encoding is detected, so the workbook opens correctly on any computer.
CSV vs XLSX
| CSV | XLSX (Excel) | |
|---|---|---|
| What it stores | Plain text, one row per line | Workbook with sheets, formats and formulas |
| Several sheets | No, one table per file | Yes |
| Formatting, filters, frozen rows | No | Yes |
| Data types | Everything is text | Numbers, dates and text are separate |
| Best for | Imports, exports and data exchange between programs | Working with the data, sharing reports |
Comma or semicolon?
In countries that write decimals with a comma, such as Germany, France, Spain or Russia, Excel saves CSV files with semicolons, because the comma is already used inside numbers. Elsewhere the comma is the standard delimiter. The converter detects both, as well as tabs and vertical bars.
If your numbers use a decimal comma, like 1234,56, choose Comma as the decimal separator so they become real numbers in Excel. When you save a CSV for a program in another country, choose the delimiter that program expects.
Tips for clean conversions
- Keep the first row for column names. It becomes a bold, frozen header with filters.
- Write dates as YYYY-MM-DD, for example 2025-03-31. Other date formats stay text, because 03/04 means different days in different countries.
- If letters look wrong in the preview, choose the encoding manually. Files from older Windows programs often use Windows-1252.
- Turn off Store numbers as numbers if every column should stay exactly as written, for example for a list of codes.
- Excel holds at most 1,048,576 rows per sheet. Split larger files before converting.
Frequently asked questions
Is this CSV to Excel converter free?
Yes. There is no sign-up, no watermark and no limit on the number of conversions. Files up to 100 MB can be converted.
Are my files uploaded?
No. The CSV is read and the Excel file is built in your browser. Your data never leaves your device, which matters for customer lists and financial data.
Will leading zeros and long numbers be kept?
Yes. Values with leading zeros, such as 00123, are stored as text when Keep leading zeros is on. Numbers with more than 15 digits, such as credit card or tracking numbers, are always stored as text, because Excel would round them.
Why do I see strange characters like é in Excel?
The file is UTF-8, but Excel read it with an older encoding. Convert it here instead: the encoding is detected and the XLSX shows every character correctly. For CSV files you create, keep the UTF-8 BOM option on.
Can I combine several CSV files into one Excel file?
Yes. Select or drop several CSV files at once. Each one becomes its own sheet, named after the file, in a single workbook.
Can I convert Excel to CSV?
Yes. Choose Excel to CSV and open an XLSX file. Pick the sheet, the delimiter and whether to add a BOM, then download the CSV or copy it. With several sheets you can download them all as a ZIP.
Does it work with old .xls files?
No. Only the current XLSX format can be opened. Open the .xls file in Excel, Google Sheets or LibreOffice and save it as XLSX or CSV first.
Are formulas in the CSV run?
No. Values that start with = are stored as plain text, never as formulas. This protects you from CSV files that try to run harmful formulas when opened.
How to Open a CSV File in Excel Without Losing Data
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