Free online CSV Data to Excel (OOXML) converter. Files are processed locally in your browser — no uploads, 100% private.
Drop your .CSV file here
or click to browse from your device
100% browser-based — no server uploads, no cloud processing
Free forever — no account or subscription required
Supports batch conversion for multiple files at once
Works on any device — desktop, tablet, and mobile
Results available in seconds — no server queue or wait time
Files are cleared immediately after processing for maximum privacy
Comma-Separated Values data
Microsoft Excel Open XML — current default format
XLSX is an industry-standard format with universal support
Source: Comma-Separated Values data
Output: Microsoft Excel Open XML — current default format
100% browser-based processing — files never leave your device
May require specific software to open or edit
Not universally compatible with all applications
Alternative formats may offer better compression or quality
File format conversion for cross-platform compatibility
Reducing file size for storage and sharing
Cross-application and cross-platform workflows
Batch processing and automation pipelines
Keep original files before converting for maximum flexibility
Test converted output before using in production workflows
Use batch processing for multiple files to save time
Match the output format to your delivery platform for best results
Drag & drop your file or click to browse
Files are processed instantly in your browser
Save your converted or processed file
Upload your CSV file using the drop zone above. Your file is instantly converted to XLSX format right in your browser — no server upload, no waiting.
Completely. Our converter processes your CSV file 100% in your browser using client-side code. It never leaves your device or touches any external server.
It depends on the formats. Converting from lossless to lossy (e.g. PNG to JPEG) may reduce quality. Converting lossless-to-lossless (e.g. PNG to WebP lossless) preserves all quality.
Free, instant, and 100% private. Your files are processed locally in your browser.