Clean CSV files

Use the CSV cleaner. Files larger than 32 MB are refused before they are read. A .xlsx workbook opens in the browser. The first row is the header, and the download is still CSV. Save .xls as .xlsx first. If a CSV uses semicolons and arrives as a single column, the cleaner offers a way to reparse it.

Quoted commas, quotes inside quotes, and line breaks inside quotes stay in the cell that contains them. Cells remain text, so a postal code of 001 is not turned into the number 1.

Trim removes spaces at the edges. Collapse repeated spaces is a separate rule for double spaces between words. Empty-row removal deletes a row only when every cell is blank. Exact duplicate removal keeps the first full row and treats case and spaces as different.

The preview lists the first changes and the row counts. Apply updates the table. Undo steps back. Reset returns to the file you opened. Download saves the table then on screen.

name,city
  Ada  ,Tokyo
Ada,Tokyo
,

Trim, then remove empty rows, then remove exact duplicates. The download contains one data row: Ada,Tokyo. The blank row is gone, and the padded copy matches the earlier Ada row only after trimming.