What is a CSV splitter?
A CSV splitter divides one CSV into smaller files while preserving record order and column values. It is useful when a file is too large for an import limit, needs fixed-size processing batches, or must be divided into a known number of assignments.
Each output can repeat the original header row so it remains understandable and ready to import on its own. Quoted delimiters, escaped double quotes, and line breaks inside quoted fields remain part of the same CSV record.
How to split a CSV file
- Open or drag in one CSV, TSV, or delimited text file up to 50 MB. Select Example to try a small customer file.
- Choose Rows per file, File size, or Number of files.
- Adjust the value. Open Settings only when you need to change the delimiter, header handling, empty rows, or file name prefix.
- Review the estimated file count and select Split CSV.
- Download individual files or select Download all as ZIP.
The tool remembers split settings in this browser, but each newly opened file starts with its own derived output name.
Split CSV example
Suppose customers.csv contains five data rows:
id,name,country
1,Alice,US
2,Bob,UK
3,Carol,US
4,David,DE
5,Elena,FRWith two data rows per file, the result is:
customers-part-001.csv 2 data rows
customers-part-002.csv 2 data rows
customers-part-003.csv 1 data rowEvery file includes id,name,country when First row contains headers is enabled. The five records keep their original order and appear exactly once.
CSV splitting methods
| Method | Best for | Result |
|---|---|---|
| Rows per file | API batches and imports with record limits | Every part has at most the selected number of data rows |
| File size | Upload, attachment, or storage limits | Records are added until the next complete record would exceed the target |
| Number of files | Dividing work or data into a fixed number of parts | Rows are distributed as evenly as possible |
Rows per file is the most predictable option. File size is measured from the serialized UTF-8 output, including a repeated header and BOM when present. Number of files gives any remainder to the earlier parts, so file sizes can differ slightly.
When should you split a CSV file?
Common cases include:
- A CRM, ecommerce platform, or database import limits rows or upload size.
- A large export needs smaller batches for an API, job queue, or test fixture.
- A dataset must be divided evenly between people or processing tasks.
- A file is inconvenient to inspect in a spreadsheet or text editor.
Use CSV Viewer when the immediate task is checking, searching, or sorting a file without changing it. Use CSV Editor when cells, headers, rows, or columns need correction before splitting.
Rows vs. file size
Choose rows when the destination limits records or when every batch should contain a predictable number of items. Choose file size when the destination limits bytes. Choose number of files when the required result is a fixed number of assignments rather than a fixed capacity.
File-size parts are not guaranteed to be equal because CSV records have different lengths. A record is never cut in half. If one complete record plus the repeated header is larger than the target, that part exceeds the target and the result reports a warning.
Why repeat the header?
A header names the columns in each part. Without it, later files can be difficult to identify and some importers may treat the first data row as column names.
The rows-per-file setting counts data rows only. Repeating the header does not duplicate a source data record. Disable the header setting only when the source has no header or the destination explicitly requires headerless parts.
CSV records are not always one text line
A quoted CSV field may contain commas, semicolons, Tabs, pipes, double quotes, or line breaks. That means splitting raw text at every newline can corrupt a valid record.
This splitter parses complete CSV records before creating parts. It recognizes comma, semicolon, Tab, and pipe delimiters, and it preserves LF or CRLF output style. Serialization may normalize unnecessary quoting, but cell strings and record order remain unchanged.
Supported files and limits
The tool accepts one CSV, TSV, or delimited text file up to 50 MB. Input must be UTF-8, with or without a UTF-8 BOM. A source BOM is repeated in every output file, while files without one remain without one.
At most 1,000 output files and 100 MB of combined output can be created in one operation. The combined limit protects against a wide header being repeated into an unexpectedly large result. A warning appears above 100 files so an accidental small row or byte limit can be corrected before creating a large download set.
Split CSV FAQ
How do I split a large CSV into multiple files?
Open the file, choose a split method and value, select Split CSV, then download the resulting files individually or together as a ZIP.
Can I split a CSV by row count?
Yes. Enter the maximum number of data rows for each output. The final file can contain fewer rows.
Can I split a CSV by file size?
Yes. Select a target in KB, MB, or GB. The tool measures serialized UTF-8 bytes and keeps every record intact, so an unusually large record can exceed the target.
Will every split CSV include the header?
Yes, when First row contains headers is enabled. The source header is repeated in every output and is not counted as a data row.
Does splitting change the data order?
No. Parts are numbered in source order, and records keep their order within each part.
How large a CSV can I split?
The current browser workflow accepts one file up to 50 MB. Actual processing time depends on row count, column count, record length, browser, and available device memory.
Can I split a CSV by a column value?
No. This tool creates sequential parts by rows, bytes, or file count. It does not group values, evaluate conditions, or clean data.
Can I combine the files again?
Yes. Use Merge CSV to append compatible parts in their numbered order.