Excel Converter
ConvertersUpload an Excel spreadsheet (.xlsx or .xls) and convert it to JSON, CSV, HTML table or SQL INSERT statements instantly in your browser. View formulas, preview multiple sheets — nothing is uploaded to a server.
About Excel Converter
The Excel Converter reads .xlsx and .xls files locally using SheetJS (xlsx) and converts each sheet to JSON arrays, CSV, styled HTML tables or SQL INSERT statements — all in your browser without any server upload. Switch between sheets via the tab bar, choose your output format, and download or copy the result in one click.
Features
- ✓Supports .xlsx and .xls formats via SheetJS
- ✓Multi-sheet support — switch between sheets with a tab bar
- ✓Four output formats: JSON array, CSV, HTML table, SQL INSERT statements
- ✓Raw formula view — see the underlying Excel formula for each cell
- ✓Column-type inference for SQL output (TEXT, INTEGER, REAL)
- ✓Download converted output as .json, .csv, .html or .sql
- ✓Copy full output to clipboard in one click
- ✓100% client-side — your file never leaves your device
- ✓Web Worker processing so large spreadsheets don't freeze the UI
Common Use Cases
- Converting business Excel reports to JSON for REST APIs or databases
- Generating SQL INSERT statements from Excel data files for bulk imports
- Previewing Excel spreadsheets without Microsoft Office installed
- Converting spreadsheet data to CSV for database migration pipelines
- Transforming Excel exports to HTML tables for embedding in documentation
Frequently Asked Questions
QDoes my Excel file get uploaded to a server?
No. The file is read entirely in your browser using the SheetJS library. Nothing is transmitted to any server at any point.
QWhich Excel formats are supported?
Both modern .xlsx (Office Open XML) and legacy .xls (BIFF8) formats are supported. .csv files can also be opened.
QCan it handle multiple sheets?
Yes. When the workbook has multiple sheets, a tab bar appears above the output panel. Click any tab to switch to that sheet's data.
QHow does SQL type inference work?
The converter inspects the first 100 rows of each column. If all non-empty values parse as integers it outputs INTEGER; if they parse as decimals it outputs REAL; otherwise TEXT.
QIs there a file size limit?
There is no hard limit, but very large files (>50 MB) may be slow since all processing runs in the browser. For very large files, a server-side tool such as Python pandas is more practical.