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Have an outdated Microsoft Office 2003?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

Rating CSV to XLSX

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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.

CSV files are lightweight and universal, but they're raw data — no formatting, no formulas, no charts. Converting to XLSX gives you a proper Excel workbook ready for analysis, visualization, and sharing. The moment the data lands in XLSX, Excel's full feature set becomes available: PivotTables, conditional formatting, VLOOKUP, data validation, and structured table references.

What You Gain by Converting CSV to XLSX

CSV Format Details

CSV is defined by RFC 4180, but the standard is loosely followed in practice. The variations that matter most when converting:

Common CSV Sources and Their Quirks

After Conversion: Formatting the XLSX as an Excel Table

Converting CSV to XLSX gets your data into a workbook. The next step takes 10 seconds and significantly improves usability:

The result is an Excel Table — a named, structured range with a distinct set of behaviors:

Online Converter vs Total Excel Converter: Feature Comparison

When the Online Converter Is the Right Choice

The online tool is the fastest option for a single CSV file with standard formatting — UTF-8, comma-delimited, no unusual characters. Upload, download, done. No installation, no account, no configuration.

It is the right choice when you need a one-off conversion and the file does not contain sensitive data.

When to Use Total Excel Converter

Total Excel Converter runs on Windows 7, 8, 10, and 11. A 30-day free trial is available — no email or credit card required.

Source	Delimiter	Encoding	Notes
Salesforce	Comma	UTF-8	Dates in ISO 8601 format; may need reformatting for Excel display
HubSpot	Comma	UTF-8	Numeric IDs exported as plain integers; phone numbers may lose leading zeros
QuickBooks	Comma	Windows-1252 possible	Older exports may be ANSI; currency symbols may garble in UTF-8 tools
MySQL / phpMyAdmin	Semicolon common	UTF-8	Default delimiter varies by export settings; verify before converting
pandas / Python	Configurable	UTF-8 (default)	Index column exported by default; strip with `index=False` or remove after import
R write.csv()	Comma	UTF-8	Row names written as first column by default; use `row.names=FALSE` to suppress
Google Sheets export	Comma	UTF-8	Consistent and clean; handles international characters correctly

Feature	Online Tool	Total Excel Converter (Desktop)
Batch conversion	No — one file at a time	Yes — entire folders, wildcards
File size limit	Yes	No practical limit
Encoding detection (UTF-8, ANSI, etc.)	Basic	Automatic detection with manual override
Delimiter detection (comma, semicolon, tab)	Basic	Automatic detection with manual override
Multiple CSVs into one workbook (separate sheets)	No	Yes — each CSV becomes a named sheet
Column formatting on output	No	Yes — number, date, text formats per column
Command-line / automation	No	Yes — full CLI, scriptable via .bat
Privacy — file stays local	No — uploaded to server	Yes — never leaves your machine
Works offline	No	Yes

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

Convert CSV to XLSX Online