Use this tool

Prepare the input and run the tool

Paste CSV text or choose a .csv file. Result: Download one or more smaller CSV files.

Split a local CSV into smaller files by data-row count. Large files are streamed in a Web Worker so the page stays responsive.

Recommended laneUp to 500MB on modern desktop browsers

Local splitNo upload; CSV files stream in a worker

Large outputsSplit files are downloaded as safe CSV parts

Best for Chrome or Edge on a desktop browser. Keep this tab open while the worker runs. For very large files, choose a larger row count such as 100,000 rows per file to avoid producing too many parts.

Drop a CSV file here

Use this before running another tool when one source file is too large for the recommended browser lane.

Rows per output file

Small CSV input

Ready.

Split CSV output summary appears here.

Data handling: This page processes only pasted text, selected files and form inputs in this browser session.

Readiness details

What to check before using the result

References and workflow

Open related workflow

Tool guide

How to use Split CSV

Use this when an upload form, email, review process, or another browser-local tool cannot handle one large CSV. The header row is copied into each split file.

What this tool does

Split a large CSV into smaller CSV files by row count in a local browser worker.

Input: Paste CSV text or choose a .csv file
Output: Download one or more smaller CSV files

Step-by-step usage guide

1Choose a local CSV file or paste a small sample.
2Set the number of data rows per file.
3Run the local worker and download the split CSV files.

Common errors and fixes

Output files have uneven row counts

The row count setting applies to data rows, while the header row is copied into every file.

Set the split size based on the destination upload limit and remember that each file will include one extra header row.

A downstream import says headers are missing

The original CSV may not have a real header row, or the first row may contain data.

Add the correct header row before splitting so every output file carries the expected column names.

Large CSV text feels slow to preview

Very large pasted files can stress the browser tab before the ZIP is created.

Use a smaller row size, close other heavy tabs, or split the source file in smaller batches.

FAQ

Is the header kept?

Yes. The first CSV row is included as the header in each split file.

How are rows counted?

The row limit applies to data rows after the header.

Can it handle very large files?

The recommended lane is up to 500MB on modern desktop Chrome or Edge. The file is streamed locally in a worker and is not uploaded.