Convert CSV to XLSX Online

CONVERT CSV to XLSX ONLINE

1) Upload CSV file to convert

Drop files here, or Click to select

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Allowed file types: fasta, qif, ofx, iif, srt, ics, excel, ris, bib, ods, xls, xlsx, xlsm, csv, tsv, tab, xlsb, xltx, xlr, pxl, qpw, wb3, wq1, dbf, wk3, 123, mdb, evtx, pages, numbers, sqlite

2) Set converting CSV to XLSX options

3) Get converted file

DOWNLOAD CONVERTED FILE

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Get Total Excel Converter to convert XLS, XLSX, ODT, XLSM, etc. safely.

Convert Excel Files in Batch!;
Convert CSV to XLSX and in many other formats
Convert hundreds of spreadsheets in 3 clicks;
Both MS Office and OpenOffice files;
Have a desktop converter that works without Internet;
Keep your files safe, don't send them to the web;
Get more accurate results with the more poweful engine.

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Total Excel Converter

Total Excel Converter supports almost all Excel extensions: XLS, XLSX, XLSM, XLSB, XLT, XLTM, XLTX, XLK, XLW. When the new Office is released, we will add new file types too.

With Total Excel Converter you can convert Excel to PDF and add a digital signature in one go.

Total Excel Converter can convert each page of your spreadsheet into a separate file.

Tell Total Excel Converter to copy original time stamps if you don't want to change the date.

Have an outdated Microsoft Office 2003? Update all your old files to the new format in one go. Convert XLS files to XLSX in batches.

Total Excel Converter will help you to convert Excel 2003 XML Files (rare option!)

Total Excel Converter has a built-in renamer to give your files new descriptive names. Include a counter, a date or worksheet name into the file name and your files will be in perfect order.

Convert Excel spread sheets via our most straightforward interface.

The widest list of output file types: DOC, PDF, HTML, MHT, XHTML, CSV, TXT, TIFF, JPEG, SVG, RTF, XML, XLS, XLSX, ODS, ODT, Lotus, DIFF, SYLK, LATEX, SQL, DBF, Access!

Total Excel Converter can combine several Excel spread sheets into one TIFF or PDF file.

Want to quickly find a file? Total Excel Converter helps you to preview any document you select.

Add your logo or any other image to the header or the footer of the output file.

Want more order? Add page counters or a date to every page of the output files. Sequential numbering of several folders is avaialble.

Total Excel Converter can copy original time stamps if you want to keep them.

When you convert Excel to PDF you can set user permissions, password-protect your files or sign with a digital signature. Get PDF, PDF/A and non-searchable PDFs.

Total Excel Converter can be run via command line (get the ready-to-use command line from GUI).

How to convert CSV to XLSX?

💾 Upload Your File: Go to the site, click on «Upload File,» and select your CSV file.

✍️ Set Conversion Options: Choose XLSX as the output format and adjust any additional options if needed.

Convert and Download: Click 👉«Download Converted File»👈 to get your XLSX file.

Cloud Based

There is no need to install any software to convert CSV to XLSX with CoolUtils. Simply access the internet, and you can easily convert your file online with our service.

Secure

Our hardware operates in top-tier, highly secure data centers equipped with advanced electronic surveillance and multi-factor access control systems.

Ease of Use

Converting CSV spreadsheets to XLSX online has never been so simple. Drop your .csv and the converter parses the delimiter-separated values and writes a proper Excel workbook — with column widths, data types, and sheet structure preserved. Compatible with Microsoft Excel, Google Sheets, and LibreOffice Calc.

Privacy

We understand the importance of privacy, which is why we've developed a comprehensive privacy policy detailing how we handle your files and personal information. You can read the policy here.

CSV File

File extension	.CSV
Category	Document File
Description	CSV is a plain text format used for representing database tables. Each data box (cell) is enclosed in commas. Each line is a table row with data cells. It is a perfect format for transporting tables from one application to another. CSV files can be edited in OpenOffice Calc, MS Excel and many others. Being a plain text in actual fact, CSV tables are compatible with various text editing programs. It doesn't support formatting, so any data structuring is made with the use of special characters.
Associated programs	The CSV file format is very simple and supported by almost all spreadsheets and database management systems
Developed by	Microsoft
MIME type	text/csv
Useful links	More detailed information on CSV files
Conversion type	CSV to XLSX

XLSX File

File extension	.XLSX, .EXCEL
Category	Document File
Description	XLSX is a format from Office Open XML family, a native MS Excel file type starting from version 2007. As opposite to XLS, this format uses ZIP compression that makes XLSX files smaller in size. Actually XLSX file is an archive of XML-documents. The cells in XLSX table can contain plain text, formulas or graphic elements. XLSX can be read in MS Office 2007 and later, Universal Viewer, OpenOffice, MS Office Excel Viewer, Corel WordPerfect Office. This format doesn’t support macros.
Associated programs	Microsoft Excel 2007 OpenOffice OxygenOffice Progessional (Linux)
Developed by	Microsoft
MIME type
Useful links	More detailed information on XLSX files

2026-04-27

Pulled a CSV export from our CRM and needed XLSX with proper column types for the finance team. Conversion preserved leading zeros in the IDs — most tools mangle those.

Linnea Karlsson

2026-03-08

Handles tab-separated and semicolon-separated CSVs too, which my locale exports use. Saved me a manual import step in Excel.

Anthony Russo

2026-01-15

Converted a 200k-row CSV to XLSX for pivot table analysis. Fast, no truncation, opened cleanly in Excel.

Kwame Asante

Rating CSV to XLSX

4.7 (410 votes)Rate It

CSV to XLSX — Frequently Asked Questions ▼

What is the difference between CSV and XLSX?

CSV (Comma-Separated Values) is plain text — rows of values separated by commas or semicolons, with no formatting, multiple sheets, or formulas. XLSX (Office Open XML, ISO/IEC 29500) is Excel's modern workbook format, supporting multiple sheets, cell formatting, formulas, charts, and data types. Converting CSV to XLSX makes data ready for Excel analysis.

Will the converter detect my CSV delimiter automatically?

Yes. The converter detects comma, semicolon, tab, and pipe delimiters automatically. European CSV files that use semicolons (because a comma is the decimal separator) are handled correctly.

Are formulas or cell formatting added during conversion?

No. The converter maps CSV columns directly to XLSX cells as plain data values. Formulas, styles, and charts are not generated automatically — add those in Excel after conversion.

What character encoding is supported?

UTF-8 (with and without BOM) is handled correctly, preserving international characters. Windows-1252 (ANSI) encoding is also supported for legacy exports from Windows applications.

Can I convert multiple CSV files to XLSX at once?

The online tool converts one file at a time. For batch conversion of dozens or hundreds of CSV files — database exports, analytics reports, IoT sensor logs — use Total Excel Converter desktop software.

How do I turn the CSV data into a proper Excel table after conversion?

Open the XLSX in Excel, select all data, and press Ctrl+T. Excel formats the data as a structured table using the first row as headers. You can then sort, filter, and add formulas.

What is the file size limit for CSV files?

The online converter handles files up to 50 MB. For large CSV files (millions of rows, big data exports), use Total Excel Converter desktop software.

Convert CSV to XLSX Online

CSV files are raw data — no formatting, no formulas, no structure beyond commas and line breaks. Converting CSV to XLSX transforms that flat text into a proper Excel workbook ready for analysis, visualization, and sharing with colleagues who use Excel. The moment data lands in XLSX, every Excel feature becomes available: PivotTables, conditional formatting, charts, and VLOOKUP.

Proper column detection — delimiters detected automatically; columns land in the right cells
Number and date formatting — numeric values recognized correctly, not stored as text
Multi-sheet support — large CSVs handled without truncation at row or column limits
No Excel required — upload from any browser without Microsoft Office installed
Files deleted after 1 hour — uploaded files are removed from the server automatically

What Is CSV?

CSV (Comma-Separated Values) is a plain-text format that stores tabular data as rows of values separated by commas or other delimiters. CSV has no concept of formatting, formulas, data types, or charts — it is pure data in the most portable form. Every database, CRM, ERP system, and data export tool produces CSV. The limitation is that raw CSV is not suitable for analysis or presentation without opening it in a spreadsheet application and applying formatting manually.

What Is XLSX?

XLSX is Microsoft Excel's Open XML spreadsheet format — the standard for business data analysis worldwide. XLSX files store values, formulas, cell formatting, charts, multiple worksheets, named ranges, and data validation rules. Converting CSV to XLSX preserves all data while making it immediately editable in Excel or LibreOffice. XLSX is the format expected by financial reporting tools, business intelligence platforms, and accounting software.

Online Converter vs Desktop Converter

Feature	Online (this page)	Total CSV Converter (desktop)
Batch conversion	✓ Single file	✓ Entire folders, recursive
File size limit	Up to 50 MB	No limit
Delimiter selection	✗	✓ Comma, semicolon, tab, pipe, custom
Automation / scripting	✗	✓ Command-line, .bat, Task Scheduler
Files stay local	✗	✓ No upload required
Price	Free	From $29.90

Batch CLI example: TotalCSVConverter.exe C:\csv_files C:\xlsx_out /ConvertTo xlsx /ProcessRecursively

How to Convert CSV to XLSX

Click Choose File and select your .csv file
The format is detected automatically
Select XLSX as the output format
Click Convert — processing takes a few seconds
Click Download to save your XLSX file
Open in Excel or LibreOffice Calc and start analyzing your data

When Do You Need CSV to XLSX?

Database exports — converting MySQL, PostgreSQL, or SQL Server exports to Excel for reporting
CRM and ERP data — Salesforce, SAP, and similar systems export CSV; stakeholders need XLSX
Financial reporting — raw transaction data from banks and payment processors arrives as CSV
Data analysis — applying Excel formulas, PivotTables, and charts to plain CSV data
Client deliverables — sending formatted XLSX reports instead of raw CSV files

Feature	Online Converters	CoolUtils Desktop	Excel Built-in	Other Software
Batch Conversion	Limited	✅ Unlimited	Manual only	Limited
File Size Limit	1-5MB	✅ No limits	System dependent	Varies
Privacy & Security	Upload required	✅ 100% offline	✅ Local only	Varies
Conversion Speed	Internet dependent	✅ Fast local processing	Slow	Medium
Advanced Options	Basic	✅ Full customization	Limited	Basic
Cost	Free/Premium	One-time purchase	Requires Office	Subscription
Formatting Preservation	Good	✅ Excellent	Good	Varies
Multiple Formats Support	Limited	✅ 40+ formats	Few formats	Limited