Split CSV File
Split a large CSV into several files in your browser. By row count, into equal parts, or one file per value in a column. Header kept on each.
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All Data tools →This tool runs entirely in your browser. Nothing you enter is sent to our servers, so there is nothing for us to store or see.
About the Split CSV File
Break one CSV into several, downloaded as a ZIP. Everything runs on your own device, so a large export of real records is never uploaded.
Three ways to split, because they answer different problems. By row count is for an import limit — a system that accepts a thousand rows at a time needs the file in thousands. Into equal parts is for dividing work between people, and the parts are balanced so their sizes differ by at most one row rather than leaving a final file with three rows in it. One file per value in a column is the one that saves real time: split by region, month or account and you get a file per value, named after it.
The header row is repeated at the top of every output file. That is the detail that makes the results usable — a part with no header is a file whose columns nobody can identify, and it is what makes splitting with a text editor such an unpleasant job.
There is a cap of five hundred parts, and it will tell you rather than silently truncating. Splitting by a column with thousands of distinct values is almost always a mistake — usually the wrong column — and an archive holding forty thousand tiny files is not a useful thing to hand anybody.
How to use the Split CSV File
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Choose your CSV
Drop a .csv file onto the box or click to pick one. Several files can be queued and each is split separately.
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Pick how to split it
By row count for an import limit, into equal parts for dividing work, or one file per value in a column.
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Set the number or the column
A row count, a number of parts, or the column to group by — named by heading or by position counting from 1.
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Download the ZIP
The archive appears on the row with a count of the parts. Each file inside carries the header row.
Frequently asked questions
Is my file uploaded anywhere?
No. The file is read and the parts are built entirely inside your browser, and nothing is sent to a server. You can disconnect from the internet once the page has loaded and it will keep working exactly as before.
Does each part keep the header row?
Yes, the header is repeated at the top of every output file. That is what makes the parts usable on their own — a file with no header is one whose columns nobody can identify, and re-adding them by hand is exactly the tedious part of splitting a CSV in a text editor.
What does splitting by a column do?
It groups the rows by the value in that column and writes one file per distinct value, named after it. Split a national export by the region column and you get a file per region. Rows with an empty value in that column are collected into their own file rather than being dropped.
Are equal parts really equal?
Their sizes differ by at most one row. A naive split leaves the last part with whatever happens to remain, which can be three rows out of ten thousand — balanced parts are what you actually want when dividing work between people.
Why is there a limit of five hundred parts?
Because an archive of forty thousand tiny files is not useful to anybody, and asking for one almost always means the wrong column was chosen. You are told the count and the limit rather than being handed a truncated result that looks complete.