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About this tool
Split a CSV file into smaller CSV files by rows per file, by an equal number of files, or one file per column value — in your browser.
Split CSV breaks one large comma-separated file into several smaller CSV files that each open cleanly in Excel, Google Sheets or a database importer. It parses the file with RFC 4180 rules, so quoted fields containing commas or line breaks are never cut in half, and it repeats the header row at the top of every output part. Use it when an upload limit, a row cap or a per-region hand-off means one file has to become many.
Open Split CSV on AltFTool — it loads instantly in your browser.
Paste or upload your source content.
Choose the target format or conversion mode.
Copy or download the converted result.
Each output file starts with the original header row, so column names survive the split.
RFC 4180 parsing means a comma or newline inside quotes never becomes an accidental split point.
Parsing, splitting and ZIP packaging all happen in the browser — no upload, no server copy.
Load the CSV, choose 'Max rows per file' and enter a row limit — a 12,000-row file split at 5,000 rows produces three files of 5,000, 5,000 and 2,000 rows. The header row is copied into each one, then you download them individually or as a single ZIP.
Yes, as long as 'First row is a header' is ticked. That first row is treated as column names rather than data and is written to the top of every output part, so all files import with the same schema.
Yes — pick 'One file per column value' and choose the column. Every distinct value becomes its own CSV named after that value, with blank cells grouped into a '(blank)' file. The split is capped at 500 output files to keep the browser responsive.
No. The file is read with the browser's own File API and split with JavaScript running on your machine; no request carries the file contents to a server, which is why the tool also works with the tab offline once loaded.
Add the Split CSVwidget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
<iframe src="https://www.altftool.com/embed/widget/split-csv"
title="Split CSV — free AltFTool widget"
width="100%" height="640" style="border:0;border-radius:12px;overflow:hidden"
loading="lazy" referrerpolicy="no-referrer-when-downgrade"></iframe>
<p style="font-size:12px;margin:4px 0 0">Widget by <a href="https://www.altftool.com/tools/all/split-csv?utm_source=embed&utm_medium=widget">AltFTool — free online tools</a></p>