Split a Large CSV File
Cut an oversized CSV into parts that Excel, Google Sheets, or your import tool will accept, with the header kept in every part.
Processed in your browser. Files never leave your device.
Up to 25 MB free, 200 MB with Structura Pro.
How it works
- Upload the large CSV file.
- Enter the rows per file, for example 1,000,000 for Excel or the row limit of your import tool.
- Click Split. Each part keeps the original header row.
- Download the ZIP and open or import the parts one by one.
When a CSV is too big to open
Excel shows at most 1,048,576 rows and Google Sheets caps a spreadsheet at 10 million cells, so a big export either opens truncated or not at all. Many import screens are stricter still, with limits such as 5,000 rows or 10 MB per upload.
Pick a row count under the limit you are working with and split. Rows are copied exactly as they are in the original file, including quoted cells that contain commas or line breaks.
Common row counts
- Excel: up to 1,048,575 data rows per file
- Google Sheets: depends on column count (10 million cells in total)
- Email-friendly parts: try 50,000 rows
Free use handles files up to 25 MB; Structura Pro handles up to 200 MB.
Related tools: CSV Splitter (full tool) · CSV Cleaner · CSV Import Validator · Data Profiler · CSV → JSON · Excel → CSV
FAQ
Does my data get uploaded or stored?
No. Processing runs entirely in your browser. Structura does not upload your files for processing and does not keep file contents on a server. Closing the tab clears the in-memory copy.
Is processing private / local-only?
Yes for the tool’s job. Your files stay on the device. Optional Cloudflare Web Analytics may record page views and anonymous events such as tool runs and downloads, never file contents or file names.
How do I open a CSV with more than a million rows?
Split it into files under 1,048,575 rows each, then open each part in Excel, or load the parts into a database.
Does each split file keep the header?
Yes, as long as First row is a header is ticked. Untick it for files without a header row.
Is there a file size limit?
25 MB free and 200 MB with Structura Pro. The file is processed in your browser, never uploaded.
Do I need an account?
No. All Structura tools are free to use without signup.
Need a data tool we don’t have yet?
Tell us what you are trying to convert, clean, compare, or validate. We prioritize tools based on real requests. Need to split by file size in megabytes instead of rows?
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