How can I split a sheet?

Two ways: into chunks of N data rows (header repeated in each), or into one file per distinct value of a column — like one CSV per region.

How do I download hundreds of parts?

Everything arrives as a single zip, built in your browser.

No artificial one — parsing runs in a background thread, so big files won't freeze the page; very large files are bounded by device memory.

Split a big CSV or Excel sheet into row-count chunks or one file per column value, downloaded as a single zip. On-device, free.