Convert CSV to XLSX
CSV to XLSX converter that runs entirely in your browser. 100% free, no signup, no upload — your files never leave your device. One-click batch conversion.
Upgrading CSV to XLSX turns plain-text rows into a real spreadsheet: sortable columns, formulas, charts, formatting, and multiple sheets. Do it when the data's destination is Excel or Google Sheets and you need actual analysis features. Watch one trap: long IDs and leading zeros need text formatting or they'll be mangled.
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All file types supported
About formats
CSV
CSV (Comma-Separated Values) is a plain-text format for storing tabular data where each row is a record and fields are separated by commas. CSV is the simplest and most universal format for exchanging tabular data between spreadsheets, databases, and statistical software. CSV files are supported by virtually every spreadsheet and data-processing tool.
- Developer
- RFC 4180 (IETF)
- Initial release
- 2005 (RFC)
- Compression
- Uncompressed
- Color depth
- 1-bit
- Transparency
- No
- Animation
- No
Best for
- Exchanging tabular data between tools
- Importing data into databases
- Statistical software data input
- Simple data export and backup
- Universal spreadsheet data interchange
Pros
- +Simplest and most universal tabular format
- +Plain-text and human-readable
- +Supported by virtually every data tool
- +No proprietary dependencies
Cons
- −No types, formulas, or formatting
- −No charts or multi-sheet support
- −Comma and newline escaping can be tricky
- −Encoding ambiguities (UTF-8 vs others)
XLSX
XLSX is the Microsoft Excel spreadsheet format introduced with Office 2007, based on the Office Open XML standard. XLSX stores worksheets containing rows, columns, formulas, charts, and styling in a ZIP archive of XML parts. XLSX is the most widely used spreadsheet format and is supported by Microsoft Excel, LibreOffice Calc, Google Sheets, and Apple Numbers.
- Developer
- Microsoft
- Initial release
- 2007
- Compression
- Lossless
- Color depth
- up to 24-bit
- Transparency
- Yes
- Animation
- No
Best for
- Financial and data analysis
- Storing formulas and charts
- Business spreadsheet sharing
- Collaborative data in Excel or Google Sheets
- Formatted tabular data with styling
Pros
- +Standard Excel spreadsheet format
- +Stores formulas, charts, and styling
- +ZIP-based OOXML open standard
- +Supported by Excel, Google Sheets, LibreOffice Calc, and Numbers
Cons
- −Not ideal for large pure-data interchange
- −Complex structure can be slow to parse
- −Formatting may differ across suites
- −Overkill for plain data tables
How to convert CSV to XLSX
- 1
Select CSV files from your computer, Google Drive, Dropbox, a URL, or by dragging them onto the page.
- 2
Choose xlsx — or any other format you need as a result (more than 200 formats supported).
- 3
Let the file convert, then download your xlsx file right away.
CSV vs XLSX
| Property | CSV | XLSX |
|---|---|---|
| Compression | Uncompressed | Lossless |
| DRM support | No | Yes |
| Open format | Yes | Yes |
When to use CSV vs XLSX
CSV
- Exchanging tabular data between tools
- Importing data into databases
- Statistical software data input
- Simple data export and backup
- Universal spreadsheet data interchange
XLSX
- Financial and data analysis
- Storing formulas and charts
- Business spreadsheet sharing
- Collaborative data in Excel or Google Sheets
- Formatted tabular data with styling
Use cases for CSV → XLSX
- Exchanging tabular data between tools
- Importing data into databases
- Statistical software data input
- Simple data export and backup
- Universal spreadsheet data interchange
- Financial and data analysis
- Storing formulas and charts
- Business spreadsheet sharing
- Collaborative data in Excel or Google Sheets
- Formatted tabular data with styling
Frequently Asked Questions
Is converting CSV to XLSX free?
Which devices and platforms can I use to convert CSV to XLSX?
Are my CSV files uploaded to a server?
Can I convert multiple CSV files at once?
What is the maximum file size?
Will converting CSV to XLSX lose quality?
Does XLSX support transparency from CSV?
How will the file size change after converting CSV to XLSX?
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200+ Formats
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