Table Converter

Every input becomes one table (a header plus rows of text) and every output starts from it, so any format converts to any other. CSV follows RFC 4180 (quotes, doubled quotes and line breaks inside a cell), and the delimiter is detected by which one gives the same column count on the most lines. Excel and Google Sheets copy cells with Tabs between them, so you can paste directly. JSON accepts an array of objects, a 2D array, an object of columns, an object of objects and JSON Lines. An .xlsx is a ZIP of XML files: it is read and written right here, with no libraries, including formulas (the computed value), dates, merged cells and multiple sheets. Transformations never change the pasted text: switching an option off undoes it. In the output, types are decided per column (if one value is not a number, the whole column stays text), numbers with a leading zero stay text, and CREATE TABLE picks INT, DECIMAL, BOOLEAN or VARCHAR by looking at every value in the column.