Excel has a hard cap of 1,048,576 rows — anything larger won't open, or crashes and loses data. Splitting a big CSV into smaller chunks is the standard workaround, but a common gap in simpler splitters undercuts it: only the first chunk keeps the header row, so opening part 2 shows unlabeled columns.
Split large CSV file online, header included in every part
This CSV splitter copies the header row into every single chunk automatically — open any part on its own and the column names are still there.
Excel 1,048,576 row limit workaround
Set how many data rows each chunk should hold (comfortably under Excel's limit) and download each piece — every one opens cleanly on its own.
Split CSV by row count, no upload
The file is read and split entirely in your browser — nothing is sent to a server, so there's no file-size ceiling imposed by an upload limit.
