Three straightforward steps
- Choose or paste the input requested by this tool.
- Configure the options and run the operation locally.
- Review and download or copy the result.
Data TOOL
CSV Splitter
Split a large CSV into smaller files by row count while keeping the header in every part.
ON-DEVICESelected input is processed in this browser.
Loading tool…
The selected input stays under your control
On-device processing means the input is handled by browser APIs on the device running this page. Closing or refreshing the page normally clears the active in-memory working session.
Read the Privacy Policy →Split a large CSV into manageable row batches
Create smaller files while repeating the header in every part.
How to use it
- Choose the CSV and a maximum row count per part.
- Confirm the detected header.
- Generate and download the numbered pieces.
Supported input
- CSV with a header row
- Large delimited tables within device memory
Worked example
Split a 50,000-row contact export into ten files of 5,000 data rows for a limited importer.
Limitations
- Rows are split by count, not grouped business values.
- All source data must still be parsed in browser memory.
Troubleshooting
- Choose a smaller batch size if the target importer rejects files.
- Verify multiline quoted records remain intact before use.
Tool-specific questions
Is the header included in every file?
Yes, each part keeps the column header.
Are rows reordered?
No, the original row sequence is retained across numbered parts.
Before you process
Can I use this csv splitter online without uploading my input?
Yes. This tool is labelled On-device, so the selected input is processed in your browser and is not sent to a ForgeMyFile processing API.
What happens if the browser cannot process it?
The tool shows a readable error and stops. It does not silently fall back to a cloud upload.
Why can performance differ between devices?
The browser is doing the work locally, so speed and practical file size depend on available memory, CPU and browser capabilities.