Excel & Data Tools
Convert Excel serial dates, format Power Query M and inspect CSV files. Useful when you are cleaning spreadsheets, debugging a Power BI query or preparing data for import.
DeveloperExcel Serial Date & Unix ConverterConvert Excel serial dates using 1900 or 1904 systems and compare Unix timestamps.Open tool ↗DeveloperExcel Column Letter & Number ConverterConvert A, AA and XFD to column indices and back.Open tool ↗DeveloperCSV Delimiter & Encoding InspectorInspect CSV delimiters, BOM, rows, column counts and quoted fields locally.Open tool ↗DeveloperCSV to JSON ConverterConvert small comma-separated tables to JSON objects entirely inside your browser.Open tool ↗DeveloperJSON Formatter & ValidatorFormat, minify and validate JSON locally with clear syntax error messages.Open tool ↗
Choosing the right tool
Convert Excel serial dates, format Power Query M and inspect CSV files. Useful when you are cleaning spreadsheets, debugging a Power BI query or preparing data for import.
Use the dedicated calculator for each distinct task. Open any tool for its formulas, worked examples and limitations. These guides are intended to make everyday calculations easier, not to replace professional review.