CSV & Excel Splitter
Cut big CSV and Excel files into smaller ones, header repeated in each.
Split by
The header row comes on top of each file and is not counted.
The rows are shared out as evenly as possible. A CSV is read twice (once to count its rows).
Every part, header included, stays at or below this size — handy for upload limits (1 MB = 1,024 KB). CSV output only.
Files are named after the values (for example Pune.csv); rows with an empty value go to “(blank)”.
Each sheet of the workbook becomes its own file, named after the sheet.
Parts
| File | Rows | Size |
|---|
About the CSV & Excel Splitter
Split a file that is too big to open, email or upload into smaller files: a fixed number of rows per file, a number of equal files, a maximum file size (to fit an upload limit such as 5 MB), or one file per value of a column — one file per branch, region, salesperson or month. Workbooks can also be split into one file per sheet. The header row is repeated at the top of every part, and the parts come in one ZIP.
CSV files are read as a stream, a few megabytes at a time, so even files of up to 2 GB that no spreadsheet can open are split without filling your memory. With the delimiter unchanged, every row is copied exactly as it was — quotes, line breaks inside cells and all. Excel parts keep the numbers, dates and number formats of a workbook, and number columns of a CSV become Excel numbers.
How to use it
- Choose a CSV, TSV or TXT file (any size up to 2 GB) or an Excel/OpenDocument workbook (up to 50 MB). For a workbook, pick the sheet.
- Check the preview and whether the first row is a header — it is repeated in every part.
- Choose how to split: Rows per file, Number of files, File size, Column value or, for workbooks, Sheets.
- Choose CSV or Excel parts, the delimiter and how the file names start.
- Choose Split and download ZIP. The list shows every part with its rows and size.
Examples
orders.csv (2,000,000 rows + header)
orders_part_001.csv … orders_part_020.csv, each with the header and 100,000 rows
contacts.csv, 23 MB; largest file 5 MB
5 files of at most 5 MB each (header included), cut only between rows
1 MB here is 1,024 × 1,024 bytes. If a single row were larger than the limit, its file would be larger too — the result says so.
sales.xlsx with a Branch column: Pune, Delhi, pune
Pune.xlsx (Pune and pune rows) and Delhi.xlsx
Values that differ only in upper/lower case or surrounding spaces go together unless you untick that. Empty values go to “(blank)”.
Common uses
- Uploading a big list to a CRM, e-mail tool, marketplace or government portal with a row or size limit.
- Sending each branch, region or salesperson only their own rows.
- Opening a CSV that has more rows than Excel’s 1,048,576.
- Saving every sheet of a workbook as its own CSV or Excel file.
- Batching data for imports that work best in smaller pieces.
The ways to split
- Rows per file: every part has that many data rows (the last one the rest).
- Number of files: the rows are shared out as evenly as possible — 10 rows into 3 files gives 4, 3 and 3. A CSV is read twice for this, once to count the rows.
- File size: a new part starts before a row would push the current one over the limit, counting the header, the line breaks and a byte-order mark. CSV output only, because an Excel file’s size is only known after it is compressed.
- Column value: one file per value, named after it (characters that file names cannot hold, such as / or :, become _). Up to 10,000 files.
- Sheets: one file per sheet of a workbook; empty sheets are skipped.
Blank lines are dropped. Quoting follows RFC 4180, so a quoted value with line breaks always stays in one row of one part.
What the parts contain
CSV parts are written as UTF-8 (tick UTF-8 BOM so that Excel shows ₹ and accents correctly). With Same as the file, each row is copied exactly as it was, apart from the encoding and the line break at its end (every part uses the file’s usual CRLF or LF); with another delimiter, the values are written again and quoted where they need it. An Excel sep= first line is repeated in each part when the delimiter stays the same. Excel parts have a bold, frozen header row; from a workbook they keep numbers, dates and number formats, and from a CSV whole numeric columns become numbers while codes such as 007 stay text.
Limitations
- CSV files up to 2 GB (the ZIP cannot exceed 4 GB) and workbooks up to 50 MB; a workbook is read whole, so save very large sheets as CSV and split that.
- Splitting a CSV by column value keeps the groups in memory until the end (files up to 800 MB), and Excel parts from a CSV are built in memory (CSV files up to 200 MB).
- Parts are always UTF-8, whatever the encoding of the original file.
- Formulas in workbooks are written as their saved values; colours, fonts and comments are not copied.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How do I split a large CSV file into smaller files?
Choose the file, keep Rows per file (or choose File size for an upload limit), set the number, and choose Split and download ZIP. Each part has the header row on top.
Can it split a CSV that Excel cannot open?
Yes. The file is read as a stream, so CSV files with millions of rows — more than Excel’s 1,048,576-row limit — split fine. Choose up to 1,048,576 rows per part if you want each part to open in Excel.
How do I split an Excel file into one file per sheet?
Choose the workbook and Sheets. Every sheet becomes a CSV or Excel file named after the sheet.
How do I split a file by a column, such as one file per city?
Choose Column value and the column. Each different value gets its own file named after it, with all of its rows and the header.
Is the header row repeated in every file?
Yes, when First row is a header is ticked. Untick it for files without a header; then no row is repeated.
Is my file uploaded?
No. The file is read and split in your browser, and the ZIP is created on your device.