Cut a CSV that is too big for Excel or an upload form into parts, header kept in each
Processed in your browser. Nothing is uploaded. Checked against sources on 16 Oct 2026.Upload forms and email often refuse a CSV over 10 or 25 MB, and Excel stops at 1,048,576 rows. This page cuts the file into parts of at most 10 MB each, or any size you choose, without changing a byte of the data: quotes, line breaks inside fields, the encoding and the header row are all kept, and every part opens on its own.
Drop your files or click to choose them.
Adjust the options and check the preview.
Download the result. Nothing was uploaded.
A CSV of a few hundred megabytes is common for exports from databases, analytics and online shops, and too big for many places it has to go: Excel opens at most 1,048,576 rows, Google Sheets 10 million cells, and upload forms often stop at 10 or 25 MB. Splitting it is the usual fix.
| Split by | Use it when |
|---|---|
| Rows per file | a system imports at most a number of rows at a time |
| Number of files | you want equal parts, for example one per person |
| Megabytes per file | an upload or email has a size limit |
| Column value | each region, branch or month needs its own file |
Nothing in the data changes. The file is cut between records, never rewritten. A record ends at a line break that is not inside double quotes, as RFC 4180 defines it, so an address with a line break in a quoted field stays in one piece. The delimiter, the quoting, the line endings and the encoding are kept byte for byte, and a UTF-8 byte-order mark is copied to every part so Excel still shows accents and other scripts correctly. UTF-16 files have to be saved as UTF-8 first.
The rest of the article, and all 6 questions about CSV Splitter, are on the CSV Splitter page.
Drop the CSV on the CSV Splitter, choose rows per file, a number of files, megabytes per file or one file per value of a column, and press Split. The parts download as one zip, named like sales-part-001.csv, each with the header row. Files up to 1 GB are split in the browser.
Excel shows at most 1,048,576 rows per sheet and cuts the rest off. Split the file into parts of 1,000,000 rows or fewer, with the header kept in each, and open the parts one by one or import them into separate sheets with Power Query.
Yes, when First row is a header is switched on, which it is by default. The header is copied to the top of every part and is not counted in the rows per file, so a part of 1,000 rows holds 1,001 lines. Switch it off for files without a header.
Parts are cut between rows, never inside one, so a part stops at the last whole row that fits. Splitting by number of files makes parts with the same number of rows, which can differ in megabytes when some rows are longer than others.
Rates and rules change; check the source before you rely on a figure.
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