CSV Splitter (by Rows)
Split a big CSV into smaller files of N rows each and download every chunk. The header is repeated by default.
Pure browser JavaScript. CSV parsing by PapaParse (MIT), self-hosted.
How to use this tool
- Paste CSV or upload a .csv file with a header row.
- Set how many data rows you want per chunk.
- Click Split, then download each chunk (or all of them concatenated).
Split a big CSV into smaller files of N rows each and download every chunk. The header is repeated by default.
How it works
The CSV Splitter takes a single large CSV file and divides it into multiple smaller files, each containing at most N data rows. This is useful when you need to import data into systems that cap the number of rows per upload, share manageable chunks with colleagues, or process sections of a dataset independently.
Paste your CSV text (or open a local file) and choose the chunk size. The tool counts data rows, excluding the header. By default the original header row is prepended to every output chunk so each file is independently usable. You can then download each chunk as a separate .csv file.
Everything runs in your browser using JavaScript. Your data never leaves your device, which makes this safe for files containing personally identifiable information, financial records, or other sensitive content.
When deciding on chunk size, consider the target system's row limit, typical memory constraints for spreadsheet software (Excel handles up to about 1 million rows), and how many chunks will be practical to process manually.
Worked example
Split a 10 000-row customer export into 1000-row upload batches
- Open your CRM export file (customers.csv, 10 000 data rows plus header).
- Paste the CSV content into the tool or use the file picker.
- Set chunk size to 1000.
- Click Split -- the tool generates 10 labelled chunks.
- Download each chunk and upload them one by one to your CRM import wizard.
10 files named chunk_01.csv through chunk_10.csv, each with the original header and 1000 data rows.
Common mistakes to avoid
- Forgetting to check whether the source file has a header row -- if it does not, setting 'repeat header' will copy the first data row into every chunk instead.
- Setting the chunk size larger than the original file, which produces a single output chunk identical to the input.
- Assuming row numbers in chunk filenames correspond to the original row numbers -- they restart from 1 in each chunk.
Key terms
- Chunk size
- The maximum number of data rows (excluding the header) in each output file.
- Header row
- The first row of a CSV that names the columns. The splitter repeats it at the top of every chunk by default.
- CSV
- Comma-Separated Values -- a plain-text format where each line is a record and fields are separated by commas (or another delimiter).
Frequently asked questions
- Is the header included in every chunk?
- Yes, by default — uncheck 'Repeat header' if you only want the header in the first file.
- Is my file uploaded?
- No — splitting runs locally in your browser via PapaParse; downloads are generated in-page.