CSV Splitter & Sampler

About CSV Splitter & Sampler

CSV Splitter & Sampler is a powerful tool for handling large CSV files. Split massive datasets into smaller chunks by row count or file size, or extract statistical samples using random or systematic sampling methods—all processed locally in your browser for complete data privacy.

What is CSV Splitter used for?

CSV Splitter divides large CSV files into smaller, manageable chunks. This is useful when you need to process files that exceed size limits of other applications, import data in batches, or share subsets of a large dataset with colleagues.

What's the difference between random and systematic sampling?

Random sampling extracts rows randomly from the entire file, giving each row an equal chance of selection—ideal for statistical analysis. Systematic sampling takes every Nth row (e.g., every 10th row), which is faster and maintains temporal patterns but may introduce bias if data has periodic patterns.

Are headers preserved when splitting?

Yes. When you enable 'First row is header', the header row will be automatically included at the top of every output chunk, ensuring each split file remains a valid, self-contained CSV with column names.

Is my data secure?

Absolutely. All processing happens locally in your browser—your CSV files are never uploaded to any server. This guarantees complete privacy for sensitive data like customer lists, financial records, or proprietary datasets.

How do I split a CSV to fit Excel's 1,048,576-row limit?

Choose 'By Rows' mode and click 'Set Excel limit', which fills in 1,048,575 data rows so each part plus its header row hits exactly Excel's hard 1,048,576-row worksheet ceiling. A pass/fail badge confirms every output file will import into Excel or Google Sheets without truncation or silent row loss.

Is upload required, or does it work offline?

No upload is required. The tool runs entirely in your browser using JavaScript, so your file is read directly from your device and never transmitted. Once the page has loaded it works offline, which is ideal for confidential datasets.

Does it support TSV and other delimiters?

Yes. Besides comma, you can pick semicolon, tab (for TSV files), or pipe delimiters, or let the tool auto-detect. The chosen delimiter is preserved in every output file.

Can I split files by exact size?

The 'By File Size' mode splits files to approximately match your target size in megabytes. Due to CSV structure (rows cannot be split mid-way), the actual file sizes may vary slightly but will be close to your specified target.

What happens with very large files?

The file is parsed and processed locally in your browser, so the practical limit depends on your device's available memory rather than any server. Very large multi-gigabyte files are best split on a desktop with ample RAM; for huge datasets, split by a row count that keeps each part comfortably under your machine's limits.