CSV Splitter by Rows

Breaking a large CSV into groups of rows, a thousand at a time, a hundred thousand at a time, whatever fits your workflow, is the most straightforward way to make an oversized file manageable, and it's the method most people reach for first when a file simply has too many rows.

Turbo CSV Splitter's Number of Rows method groups rows this way directly: every output file gets the same number of data rows, up to a ceiling of 1,000,000 rows per file. A five-million-row export split at 500,000 rows per group becomes ten evenly-sized files.

Each row group is written as an independently valid CSV file, with the header repeated at the top, so every group can be opened, imported, or shared on its own without needing the other files for context.

Because the split is purely row-count based, the resulting groups are predictable: you know in advance roughly how many files you'll get by dividing the total row count by your chosen group size, and Preview confirms the exact row count and estimated file count before you commit.

The streaming engine handles row grouping on files of any size, processing row by row rather than loading the whole file into memory, so grouping rows in a multi-million-row file works the same way as a small one, just taking longer proportionally.

Everything runs offline, entirely on your own PC, so splitting a file into row groups never requires uploading your data anywhere. Delimiter and encoding both default to Auto and are detected directly from the file itself, so you only need to touch them in the rare case detection gets something wrong, an unusual delimiter or a legacy encoding, for example. This makes the tool equally useful for data analysts working with irregular exports, developers automating a recurring pipeline step, e-commerce teams distributing catalog data by category, and anyone else who regularly runs into the practical limits of opening a large CSV file directly in a spreadsheet program.

1. Install Turbo CSV Splitter on your Windows PC.
2. Browse to or drag and drop your CSV file.
3. Choose your output folder.
4. Select the Number of Rows split method.
5. Set your desired rows per group, up to 1,000,000.
6. Run Preview to confirm the row count and estimated groups.
7. Click Start Split and monitor progress.
8. Open the output folder to find your row groups.
9. Adjust the parallel worker slider (1-128) if compressing many output parts.
10. Check the status bar for the final row count and file count summary.

• Groups rows into consistently-sized output files
• Up to 1,000,000 rows per group
• Header repeated on every group for independent validity
• Predictable output file count based on your chosen group size
• Preview confirms exact row count before splitting
• Works on files of any size via streaming
• Runs fully offline with no uploads required
• One-time purchase for Windows, with Gumroad license activation
• Compression options: uncompressed, per-part ZIP/gzip, or a single bundled archive
• Works with files on local drives, external drives, and network shares