Split a CSV file
Large CSVs get rejected everywhere — import limits, email attachment caps, spreadsheet row ceilings. This splits one file into numbered parts of whatever size you choose, and repeats the header row at the top of every part so each piece opens cleanly on its own.
How to use it
- Choose your CSV file.
- Set how many rows each part should contain (the header doesn't count towards this).
- Click Split, then download the parts individually or all together as a zip.
Questions
Is my file uploaded anywhere?
No. This page contains the whole tool — the JavaScript that does the work runs inside your browser tab, on your own machine. There is no server to upload to. You can confirm it yourself: open your browser's developer tools, switch to the Network tab, and run the tool. You will not see your file go anywhere. You can also disconnect from the internet after the page loads and it will still work.
Does each part keep the header row?
Yes, by default. Every part starts with the same header your original file had, so each one imports correctly on its own. You can turn this off if you plan to concatenate the parts again later.
How large a file can it handle?
The practical limit is your available memory, since the file is held in your browser rather than streamed through a server. Files up to a few hundred megabytes are normally fine on a modern laptop. Very large files are slower on first load but the split itself is quick.
What happens to commas inside quoted fields?
They're preserved. The file is parsed as proper CSV rather than split on raw commas, so quoted fields containing commas, line breaks or escaped quotes survive intact.