Split CSV
Cut a large CSV into smaller files, with the header in each.
Drop a CSV file here
or select to choose from your device
Files are processed on this device. Nothing is uploaded.
How to use Split CSV
- Add the CSV file.
- Choose a maximum number of rows per file, or how many files you want.
- Select Split CSV and download the parts one by one or as a ZIP.
How it works
The file is parsed as CSV before it is divided, so a quoted field that contains line breaks is never cut in half, the mistake made by tools that simply count lines. The original delimiter is kept, and the header row is repeated at the top of every part so each file can be imported on its own.
Typical reasons to split: an import tool with a row limit (many CRMs and mail tools accept 1,000 to 10,000 rows at a time), a spreadsheet that slows down with huge files, or a file too large to e-mail. Parts are numbered in order: name-part-01.csv, name-part-02.csv…
Files are read and written by your browser on your device. Nothing is uploaded, so there is no size limit set by us and no copy of your data anywhere else.
Example
A 25,000-row contact list split at 10,000 rows gives three files of 10,000, 10,000 and 5,000 rows, each starting with the header.
Frequently asked questions
Will every file have the header row?
Yes, when "First row is a header" is ticked. Untick it for files without a header.
How large a file can it split?
It depends on your device’s memory, because the work happens in the browser. Files of a few hundred megabytes are fine on a typical computer; on a phone, stay under about 100 MB.
Does it change my data?
No values are changed. Fields are re-quoted in the standard way where needed (for example when they contain the delimiter).
Can I split by file size?
Not directly. Choose a row count that gives the size you need; the result list shows each part’s size.
Limitations
- Splits by row count or number of parts, not by megabytes or by column value.
- One file at a time.
- The whole file must fit in memory.
Last reviewed November 9, 2026. How we build and test tools.