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CSV Splitter

Cut a big CSV into manageable files: a fixed number of rows each, a chosen number of equal parts, or one file per value of a column.

Processed locally in your browser

Options

A header name or a 1-based column number.

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The result will appear here.

What is CSV Splitter?

Very large CSV files are hard to open in a spreadsheet and rejected by many import forms that cap the number of rows or the file size. Splitting them into smaller CSV files, each starting with the same header row, solves both problems without losing any data.

This splitter parses the CSV correctly, so quoted cells with commas or line breaks are never cut in the middle, then offers three modes: N rows per file, K equal parts, or one file per distinct value of a column (for instance one file per country). It writes up to 200 files, names them with your prefix and a running number or the column value, and shows a summary table with the rows and bytes of each file.

How does it work?

  1. Paste your CSV or open a file, and say whether the first row is a header.
  2. Choose the mode: rows per file, number of equal parts, or column value, then fill in the matching number or column name.
  3. Decide whether the header is repeated in every file, set a file-name prefix and, if needed, another output delimiter or a UTF-8 BOM for Excel.
  4. Click Split CSV, review the summary table and download the files.

Common use cases

  • Fitting a 2-million-row export under the 100,000-row limit of a CRM or e-mail platform import.
  • Sharing one file per region, country or sales rep from a single master sheet.
  • Sending a mailing list in batches to stay within a provider’s sending limits.
  • Opening a huge log or dataset in a spreadsheet by working on it one part at a time.

Examples

Try this input in the tool above:

Input
id,name,country
1,Alice,FR
2,Bob,ES
3,Chloé,FR
4,David,BE
5,Emma,ES
6,Farid,FR
7,Gina,BE
Output
# | File | Data rows | Rows | Size (bytes)
1 | part-001.csv | 1–3 | 3 | 47
2 | part-002.csv | 4–6 | 3 | 47
3 | part-003.csv | 7–7 | 1 | 25

Privacy

CSV Splitter runs entirely in your browser. The text or files you provide are processed on your device and are not uploaded, logged or stored on our servers.

Limitations

Everything is processed in memory in your browser and at most 200 files are produced; if the settings would create more, the tool asks you to choose a larger chunk size or a column with fewer distinct values.

Frequently asked questions

Is the header repeated in every file?

Yes by default, so each file can be imported on its own. Untick the option to keep the header only in the first file, or untick "first row is a header" if your CSV has none.

How are the rows shared when I ask for a number of parts?

Rows are spread as evenly as possible: 10 rows in 3 parts gives 4, 3 and 3. If you ask for more parts than there are rows, you get one row per file and a warning.

How are files named in the column-value mode?

The prefix, a hyphen and the value, cleaned to letters, digits, dots, hyphens and underscores (for example part-France.csv). Empty values go to part-empty.csv and two values that clean to the same name get a numeric suffix.

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