Convert CSV to XLSX online with numbers and dates as real Excel values and IDs kept intact. Upload files up to 20GB and download the converted result in a few clicks.
Convert XLSX to CSVDrag & Drop your CSV file here
CSV files, up to 20GB
Files stay private.
Automatically deleted after 24 hours.
Link
20GB upload limit.
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Trusted for 1,827,796+ conversions
HOW IT WORKS
Three steps, no account, nothing to install.
01
Add your CSV
Drag and drop or upload the CSV you want in Excel. Comma, semicolon, tab and pipe separators all work, in UTF-8, UTF-16 or an older Windows code page.
02
Convert to XLSX
Keep XLSX as the output format and start the conversion. Numbers, percentages, ISO dates and TRUE/FALSE become real Excel values, while codes such as ZIP codes stay text.
03
Download the workbook
Download one .xlsx file with your data on Sheet1. When the first row looks like a header, it is made bold and frozen, and columns are sized to fit the content.
CSV
CSV is a plain-text table in which each line is a row and the values are separated by commas, or by semicolons in many European exports. Banks, online shops, CRMs and databases export CSV, but the file itself does not say which encoding or separator it uses.
XLSX
XLSX is the Microsoft Excel workbook format used since Excel 2007, based on Office Open XML. It stores typed cells such as numbers, dates and text, plus formatting and several sheets, and opens in Excel, LibreOffice Calc and Google Sheets. One sheet holds up to 1,048,576 rows and 16,384 columns.
FILE FORMATS
SOURCE
Comma-separated values is the simplest way to move a table between programs. Each line is a row, and quotes protect values that contain commas or line breaks. CSV has no formulas, formatting or multiple sheets, which is exactly why databases, CRMs, accounting tools and data scripts all import it.
TARGET
Excel 2007 introduced XLSX, part of the Office Open XML standard. It holds multiple sheets with formulas, formatting, charts, tables and pivot tables, up to 1,048,576 rows and 16,384 columns per sheet, and it can't contain macros (that needs .xlsm). Excel, Google Sheets, Numbers and LibreOffice all open it.
| Feature | CSV | XLSX |
|---|---|---|
| Developed by | No owner (RFC 4180) | Microsoft (ISO OOXML) |
| File extension | .csv | .xlsx |
| Editable | Yes (text) | Yes |
| Layout | Rows of values | Grid of cells |
| Best for | Importing data into other systems | Spreadsheets everywhere |
| Opens in | Spreadsheets, databases, code | Excel, Google Sheets, Numbers |
USE CASES
Practical workflows where CSV to XLSX conversion is useful.
Open a European bank export
A semicolon CSV with amounts like 1.234,56 becomes a workbook where those amounts are real numbers you can sum, with the thousands separators kept as a number format.
Keep ZIP codes and long IDs intact
ZIP codes such as 02134, phone numbers and IDs longer than 15 digits stay text exactly as written. IDs of 12 to 15 digits without a leading zero become numbers, which Excel shows in scientific notation until you give the column a number format such as 0.
Read exports from older business software
CSV files from older accounting or ERP systems saved in a Windows code page, such as Cyrillic, Greek, Turkish or Central European, are detected from the text, so names come through as real letters.
Open Japanese, Chinese or Korean CSV files
Files saved in Shift_JIS, GB18030/GBK, Big5 or Korean EUC-KR are recognized, including half-width katakana from Japanese bank exports.
Send a spreadsheet to non-technical colleagues
Share a ready-to-use .xlsx instead of a raw CSV, with a bold, frozen header row and columns sized to fit.
Work with more than a million rows
Rows beyond Excel's limit of 1,048,576 continue on Sheet2, Sheet3 and so on with the header repeated, instead of being cut off.
Sort and filter by real dates
ISO dates such as 2026-10-26 and ISO date-times become real Excel dates, so you can sort, filter and group them by month right away.
Open database and command-line exports
Pipe- and tab-separated exports from databases and developer tools are recognized, so each field lands in its own column.
Keep downloaded data from running as formulas
Text that starts with = is stored as text and never becomes a formula, which keeps cells from web forms or third-party exports inert.
Upload to an XLSX-only portal
Supplier portals, grant systems and HR tools that accept only .xlsx take the converted workbook, with numbers and dates already typed.
SUPPORTED FILES
CSV files from any system and region are supported.
The separator is detected automatically.
1.234,56 is read correctly in semicolon and tab files.
UTF-8, UTF-16, Windows code pages, Shift_JIS, GBK and more.
Rows beyond 1,048,576 continue on Sheet2, Sheet3 and so on.
Leading zeros, phone numbers and IDs longer than 15 digits stay text.
TROUBLESHOOTING
These explain most surprises.
01
Dates like 10/26/2026 or 26.10.2026 are ambiguous, so they stay text. ISO dates become real dates.
02
Excel stops at 1,048,576 rows, so extra rows go to the next sheet with the header repeated.
03
Files with more than 16,384 columns exceed Excel's limit.
04
Cells longer than 32,767 characters are cut to Excel's limit.
05
Images, PDFs and Excel files renamed .csv are refused.
06
Files with only separators or blank fields can't be converted.
Excel, Google Sheets and a few lines of Python can do this conversion if you have them set up. dragdropdo converts CSV to XLSX in the browser, with nothing to configure.
| What matters | dragdropdo | Spreadsheet Apps and Scripts |
|---|---|---|
| Nothing to install | ✓Yes. Runs in any modern browser. | ~Spreadsheet apps or a Python setup. |
| Works on phones and tablets | ✓Yes. Desktop, Android, iPhone and iPad. | ~Spreadsheet apps work on phones; scripts don't. |
| Batch conversion | ✓Yes. Add many files and download one ZIP. | ~Scripts can; spreadsheet apps go one file at a time. |
| Share finished files | ✓Yes. Send a unique link from the result page. | ~You upload and share the files yourself. |
| Pricing | ✓Free with daily limits. $2.99 or $6.99 passes for unlimited use, no monthly plan. | ~Free (Google Sheets, LibreOffice, Python) to subscription (Excel). |
| Choosing the output layout | ✓Not in the converter. The layout is fixed. | ~Yes, with export options or code. |
Other tools use different pricing, limits and workflows. This comparison describes dragdropdo's own features without assuming every other tool works the same way.
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WHY DRAGDROPDO
Convert CSV to XLSX in your browser, with nothing to install and nothing kept after 24 hours.
Private by default
Files are encrypted in transit and deleted from our servers automatically after 24 hours.
No install required
Convert in any modern browser on Windows, Mac, Linux, Android, iPhone or iPad. No app and no sign-up wall.
Big files and batches
Upload files up to 20GB each, add several at once, and download the results one by one or as a ZIP.
Share & download
Save finished files to your device or pass them on with a share link from the result page.
MORE CSV TOOLS
CSV (Comma-Separated Values) is a versatile file format used for storing tabular data in plain text. It facilitates easy data exchange between applications, supports various programming languages, and is widely compatible with spreadsheet software. Ideal for data analysis, reporting, and sharing datasets, CSV files are essential for data-driven tasks, ensuring simplicity and accessibility across platforms.
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FAQ
Answers to common questions about dragdropdo's CSV to XLSX converter.
