Data and spreadsheet tools
CSV is a family of conventions rather than a format, which is why an export that one program writes happily is unreadable in another. The delimiter, the quoting style, the line ending and the character encoding are all places where two tools can disagree while both claiming CSV support.
The cleaner exists to make that visible and fixable. It detects the delimiter, reports the row and column counts, names the specific rows that parsed oddly, and refuses to discard cells to make a grid look tidy.
One feature here has a real security consequence: the formula-injection-safe export. A cell arriving from an untrusted source and beginning with an equals sign is a formula to a spreadsheet application, and it runs when somebody opens the file.
What people use these for
- An export that opens as a single column because it is semicolon-separated.
- A UTF-8 byte-order mark glued to the first column name so lookups silently miss.
- Removing duplicate rows from three mailing lists concatenated together.
- Turning a JSON array of objects into a table, or a table into JSON.
- Preparing a file that will be opened in Excel by someone else, with the right encoding marker.
Privacy in this section
Spreadsheet exports are usually customer or transaction records, so rows are parsed in a Web Worker on your device and the file is never transmitted. The whole file is held in the tab, which is why the size cap is 50 MB.