Why convert XLSX to CSV?
Converting from Microsoft Excel Spreadsheet (XLSX) to Comma-Separated Values (CSV) is a common need in daily workflows. Whether you need to import data into a spreadsheet, export for analysis, or transform data for an API, choosing the right data format is essential.
With OmniConvert, the entire XLSX to CSV conversion process happens right in your browser using SheetJS — a pure JavaScript library that works on every device, including mobile phones. No plugins, no installs, no file uploads. Your data stays 100% private and never leaves your device.
Key Benefits of OmniConvert
Privacy Protected
Your XLSX files are converted locally in your browser. Never uploaded to servers.
Fast & Free
No waiting queues, no subscriptions. Convert unlimited files.
High Quality
Advanced algorithms ensure your CSV output preserves the highest quality.
Works Offline
Functions without internet after initial load via PWA support.
How to Use
Drag and drop your XLSX file into the conversion area above.
The browser processes the conversion instantly — no waiting required.
Click the download button to save your new CSV file.
XLSX vs CSV: Quick Comparison
| Feature | XLSX | CSV |
|---|---|---|
| Compression | ZIP-based (XML inside) | None (plain text) |
| Transparency | N/A | N/A |
| Color Depth | N/A | N/A |
| Animation | N/A | N/A |
| Best For | Spreadsheets, formulas, charts, multi-sheet workbooks | Simple tabular data, data exchange, imports/exports |
Understanding XLSX and CSV Formats
XLSX is best suited for spreadsheets, formulas, charts, multi-sheet workbooks. It uses zip-based (xml inside) compression and does not support transparency. On the other hand, CSV excels at simple tabular data, data exchange, imports/exports, using none (plain text) compression without transparency. Understanding these differences helps you choose the right format for each project and workflow.
Common Use Cases for XLSX to CSV Conversion
Data analysts converting XLSX to CSV for compatibility with different data analysis tools and spreadsheet applications.
Developers transforming XLSX data exports to CSV format for integration with web APIs or databases.
Business users preparing XLSX reports in CSV format for stakeholders who prefer a different tool.
Automating data pipeline transformations by converting XLSX files to CSV for downstream processing.
Pro Tips for XLSX to CSV Conversion
OmniConvert uses SheetJS (pure JavaScript) for data conversion — no WebAssembly needed, works on all devices including mobile.
Your data files are processed entirely in your browser — they never leave your device, ensuring complete privacy.
The conversion is near-instant for most files. Large spreadsheets (100K+ rows) may take a few seconds.