Free CSV to Excel conversion
CSV to Excel Converter – Convert CSV to XLSX
Choose a CSV, TSV or TXT file, or paste CSV data, to create an Excel (.xlsx) workbook. Your original values stay as text by default, and your file is never uploaded to our servers.
Convert CSV to Excel
Your CSV data
Excel preview
Check your dataChoose a CSV, TSV or TXT file (up to 25 MB), or paste data. Review your table, then convert and download your Excel file.
How do I convert CSV to Excel online?
Choose a CSV file or paste your data into the converter above. Check that the preview shows the right columns. If you selected a file, you can also change its encoding. Leave Detect Numbers and Dates unchecked (the default) to keep IDs, dates and long numbers as text. Click Convert CSV to Excel and download the XLSX workbook. Your CSV stays in your browser.
How to Convert CSV to XLSX
Choose or paste CSV data
Choose a CSV, TSV or TXT file, paste your data, or try an example. The preview appears before conversion.
Check the preview and options
Choose the separator, check your first row, and leave Detect Numbers and Dates unchecked to keep values such as 00123 unchanged.
Convert and download XLSX
Click Convert CSV to Excel, then Download XLSX File. The result contains one worksheet.
CSV to Excel Converter: Supported Formats and Limits
Check which files you can open and how much data you can convert.
| Input | CSV, TSV, TXT or pasted delimited text |
|---|---|
| Output | One XLSX file with one worksheet |
| Maximum size | 25 MB per file or pasted text |
| Rows and columns | Up to 2 million cells in total, with no more than 1,048,576 rows or 16,384 columns |
| Column separator | Auto detect, comma, semicolon, tab, custom |
| File encoding | UTF-8, UTF-16, ISO-8859-1 and Windows-1252 |
| Numbers and dates | Kept as text by default; optionally convert clear numbers, YYYY-MM-DD dates and true/false values |
| Privacy | Local browser conversion, free, no account or file upload |
Blank rows are skipped. If a row has fewer entries than the others, the remaining cells are left empty. The first row stays as written, even with repeated or blank column names.
CSV to Excel Example: Keep IDs and Dates Unchanged
This example includes product codes starting with zero, a 20-digit ID, names in different languages, and a date that could mean March 4 or April 3.
Sample CSV
Product ID,Name,Amount,Order Date,Company
00123,José,129.50,03/04/2026,"ACME, Inc."
00045,李雷,89.00,2026-01-15,東京 Office
12345678901234567890,東京,0.05,2026-02-02,Bright LabsWhat the Excel file will contain
With Detect Numbers and Dates left unchecked, 00123, 129.50 and 03/04/2026 stay as written. The 20-digit product ID is kept too.
Download the sample CSV, choose it in the converter above, then click Convert CSV to Excel to make your Excel file.
Try CSV to XLSX nowAfter downloading the XLSX, open it in Excel to check that the product IDs, dates and names still look right.
How to Convert CSV to Excel Without Losing Leading Zeros
Excel may treat a product code such as 00123 as the number 123. To keep the zeros and protect long IDs, leave Detect Numbers and Dates unchecked. Turn it on only if you want to calculate with numbers or work with dates in Excel.
| Original CSV value | Default: keep as text | Detect Numbers and Dates enabled |
|---|---|---|
00123 | Text 00123 | Text 00123 (zeros preserved) |
12345678901234567890 | Original 20 digits | Original 20 digits (kept as text) |
129.50 | Text 129.50 | Number 129.5 |
03/04/2026 | Text unchanged | Text unchanged (day/month order unclear) |
2026-01-15 | Text unchanged | Excel date (January 15, 2026) |
Excel can also change values when importing CSV directly. See Microsoft’s guide to leading zeros and long numbers.
Why Is My CSV in One Column or Showing Garbled Text?
| What you see | Likely cause | What to do |
|---|---|---|
| Everything in one column | Wrong separator | Try comma, semicolon or tab. |
| Names or foreign characters look garbled | File was read using the wrong encoding | If you chose a file, try a different File encoding and check the preview. |
00123 becomes 123 | ID was treated as a number | Leave Detect Numbers and Dates unchecked and convert again from the original CSV. |
| A date is read as the wrong day or month | Unclear date order | Leave Detect Numbers and Dates unchecked so the original date stays as text. |
| A company name becomes two columns | Unquoted comma | Use double quotes, for example "ACME, Inc.". |
For more about Excel CSV encoding, see our CSV UTF-8 guide.
CSV vs XLSX: What Changes After Conversion?
| Feature | CSV file | Excel file you download |
|---|---|---|
| Rows and columns | Plain text | One Excel worksheet |
| Numbers and dates | Stored as text | Text by default; can be converted to numbers and dates |
| Formulas | Does not store Excel formulas | You can add formulas after opening the XLSX in Excel |
| Colors and styling | Not stored | You can format the workbook in Excel after downloading |
| Multiple sheets | One table per file | This converter creates one worksheet per download |
| Filters and frozen headers | Not available | You can add filters and freeze the top row in Excel afterward |
Your CSV stays on your device
Your file is opened, previewed and converted to XLSX in your browser.
Processed locally
Your CSV file is read and converted right here in this browser tab.
No account required
No account, email address, or payment details required.
Ready to open in Excel
Your download contains one Excel worksheet, and your CSV is not sent to our servers.
Frequently Asked Questions
How do I convert CSV to Excel online?
Choose a CSV file or paste text, check the preview and column separator, then click Convert CSV to Excel and download the XLSX. The conversion runs in your browser.
Can I convert CSV to XLSX without Microsoft Excel?
Yes. This free converter creates an XLSX workbook locally, with no account, installation, or file upload to our servers.
Will CSV to Excel preserve leading zeros?
Yes. By default, Detect Numbers and Dates is turned off, so values such as 00123 and long IDs stay as written. Even if you turn it on, leading-zero IDs and very long numbers stay as text.
How are dates and numbers handled?
By default, all values stay as text. Turn on Detect Numbers and Dates if you want values such as 129.50 to become numbers and YYYY-MM-DD dates to become Excel dates. A date such as 03/04/2026 stays as text because the day and month order is unclear.
Why does CSV appear in one Excel column?
The file may use a different column separator than expected. Choose Comma, Semicolon or Tab under Column separator and check the preview.
What is the file size limit?
You can choose a file up to 25 MB. The converter also supports up to 2 million cells, within Excel’s maximum of 1,048,576 rows and 16,384 columns per sheet. Split larger files before converting.
Can I paste CSV data instead of choosing a file?
Yes. Paste your data into the box, check the preview and click Convert CSV to Excel. File encoding only applies when you choose a file from your device.
What does Use first row as column names do?
It shows your first CSV row as column headings in the preview and keeps that row in the Excel file, even if some names are blank or repeated. If you turn it off, Column 1 and Column 2 are only preview labels; they are not added to the download.
Is my CSV uploaded to a server?
No. Your CSV file and its contents are processed in the browser. No account is required.
Learn More About Excel and CSV
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Ready to convert CSV into Excel?
Choose or paste your CSV, check the preview, then convert and download an Excel file.