How to use the Split CSV
- Paste the CSV, or click Open file and choose a .csv (Excel .xlsx works too).
- Pick how to split: Rows per file, Number of files, or Column value to get one file per region, month or customer.
- Keep Repeat the header row on so every file opens with column names, and choose CSV or Excel output.
- Download single files from the list, or click Download all (ZIP).
Why split a CSV file?
Big CSV exports run into limits all the time: email attachments, CRM and newsletter importers that accept 5,000 or 10,000 rows per upload, Google Sheets’ 10-million-cell cap, and Excel’s 1,048,576-row maximum. Splitting turns one unwieldy file into pieces each system accepts — without opening a spreadsheet or writing a script.
Three ways to split
| Split by | Use it when | Example |
|---|---|---|
| Rows per file | An importer has a row limit | 25,000 contacts → 5 files of 5,000 |
| Number of files | You’re sharing work evenly | A lead list split between 4 sales reps |
| Column value | Each group goes somewhere different | One file per region, store or month |
What stays the same
- The header row is repeated at the top of every file, so each piece imports on its own.
- Quoted values — commas, quotes and line breaks inside cells — are written back correctly.
- The delimiter is detected (comma, semicolon, tab or pipe) and reused in the output.
- Row order is preserved inside each file.
Need to go the other way? Combine data with Remove Duplicate Lines, or convert the pieces with CSV to JSON and CSV to SQL.
Also searched as: split csv file, csv splitter, split large csv, split csv into multiple files, csv split by rows, split csv by column, divide csv, chunk csv.
Tools that pair well with the Split CSV
- Split Excel — Split a large .xlsx into smaller workbooks — by rows per file, number of files, column value (one file per region, team or month) or one file per sheet.
- JSON to Excel — Turn a JSON array into a real Excel workbook.
- Excel to JSON — Open an .xlsx workbook or paste cells straight from Excel or Google Sheets and get clean JSON.
- JSON to SQL — Paste a JSON array and get SQL that creates the table and inserts every object as a row — nested objects become columns or JSON values, and every string is escaped for your dialect.
Frequently asked questions
Is my CSV uploaded?
No. The file is read and split in your browser, so the data never leaves your device. You can even go offline after the page loads.
How large a CSV can I split?
Files of tens of megabytes and hundreds of thousands of rows work in a modern browser. The limit is your device’s memory, not a server quota.
Can I split by a column such as country or date?
Yes. Choose Column value and pick the column; you get one file per distinct value, named after it. Empty values go into a “blank” file.
Will Excel open the files correctly?
Choose Excel .xlsx as the output to avoid delimiter and encoding issues entirely, or keep CSV for importers and databases.
Can I install Split CSV as a web app and use it offline?
Yes. Split CSV is an installable web app (PWA) — installed from your browser, not downloaded from an app store. Click Install app at the top of this page in Chrome or Edge (Windows, macOS, Linux, ChromeOS) or on Android, use Share → Add to Home Screen on iPhone and iPad, or File → Add to Dock in Safari 17+ on a Mac. It then opens in its own window with its own icon, and because it runs entirely in your browser it keeps working offline. Firefox on desktop can’t install web apps. How installing works.