What is the CSV Splitter?

A CSV Splitter breaks a single large CSV file into multiple smaller files. This is necessary when a file is too large to open in Excel or Google Sheets, exceeds an import tool's row or size limit, or needs to be divided into batches for processing.

The tool lets you choose how to split — by a fixed number of rows per file, or by a maximum file size — and preserves the header row in every output file so each chunk is independently usable.

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How to Use the CSV Splitter

1. Upload your CSV file. Drag and drop it onto the upload area or click to open the file picker. The tool reads the file locally and shows you the filename, size, row count, and column headers.
2. Select your delimiter. Choose comma, semicolon, tab, or pipe depending on how the file is structured. This ensures rows are parsed correctly before splitting.
3. Set your split method. Choose between:
   • By row count — each output file will contain exactly that many rows (plus the header)
   • By file size — each output file will stay under the specified size limit
4. Preview the output. The tool shows how many files will be generated before you commit to splitting.
5. Split and download. Click to process the file. All output files download together as a ZIP archive, each named sequentially and each containing the original header row.

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Why Files Need Splitting

Excel row limit — Excel supports up to 1,048,576 rows per sheet. Any CSV with more rows than this cannot be opened in full. Splitting into chunks under one million rows solves this.

Google Sheets cell limit — Google Sheets limits files to 10 million cells total. A CSV with 100 columns hits this at 100,000 rows. Split accordingly before importing.

CRM and marketing platform limits — Tools like Mailchimp, HubSpot, and Salesforce impose per-import row limits (typically 50,000–500,000 records). Splitting your contact list into chunks keeps each import within bounds.

Database import tools — Many database GUIs and migration tools have file size or row count limits per import operation. Splitting lets you import in sequential batches.

API rate limits — When loading data through an API that accepts batches of a fixed size, pre-splitting the CSV to match the batch size simplifies the process.

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Header Preservation

Every output file includes the original header row as its first line. This means each chunk is a complete, standalone CSV — not a fragment that requires the first file to understand its column structure. Most import tools, databases, and spreadsheet applications expect a header on line 1 and will map columns correctly from each file.

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Privacy

Your CSV file is read and processed entirely within your browser. No file content is uploaded to any server, and nothing is stored after you close the tab.