BYTETOOLS

CSV Splitter

Split a large CSV into smaller files by rows per file or number of files, repeating the header in each part. Free online CSV splitter, 100% in your browser.

Drop a .csv file here or click to browse

What is the CSV Splitter?

The ByteTools CSV Splitter breaks a large CSV into smaller, manageable files. Choose how many rows each part should hold, or how many parts you want, and the tool divides the data evenly and repeats the header row in every file so each one opens correctly on its own.

  • Split by rows per file or by number of files
  • Header row repeated in every part
  • Numbered, zero-padded file names that stay in order
  • Row count and preview for each part
  • Handles quoted fields, embedded commas and newlines
  • 100% private — CSV never leaves your browser

How to use the CSV Splitter

  1. 1

    Paste your CSV, or drop a .csv file — the file name becomes the prefix for the parts.

  2. 2

    Choose whether to split by rows per file or by number of files, and enter the amount.

  3. 3

    Keep 'Repeat the header in every file' ticked so each part is self-contained.

  4. 4

    Click Split CSV, then download the parts individually or all at once.

About the CSV Splitter

The ByteTools CSV Splitter breaks a large CSV into smaller, manageable files. Choose how many rows each part should hold, or how many parts you want, and the tool divides the data evenly and repeats the header row in every file so each one opens correctly on its own.

It is built for import limits, email attachments and tools that choke on huge files — splitting a 50,000-row export into 500-row chunks takes one click. Each part is listed with its row count, ready to preview, copy or download individually, and the file names are numbered so they stay in order.

Everything runs 100% locally in your browser with JavaScript. Your CSV is never uploaded, logged or stored, so even a large file full of customer data stays entirely on your machine.

Frequently asked questions

How do I split a large CSV file into smaller files?

Paste or drop the CSV, choose 'Rows per file' and enter a number such as 500, then click Split CSV. The tool creates numbered parts, each with the original header row, that you can download one at a time or all together.

Does each part keep the header row?

Yes, as long as 'Repeat the header in every file' is ticked. That makes every part a valid standalone CSV that opens in a spreadsheet or imports correctly without you re-adding the column names.

Can I split a CSV into an exact number of files?

Yes. Switch the mode to 'Number of files' and enter how many you want. The rows are divided as evenly as possible, so the final part may hold slightly fewer rows than the others.

Why are the files downloaded separately instead of as a ZIP?

Everything runs in your browser without extra libraries, so there is no archiving step. Each part downloads as its own .csv file, and your browser may ask permission once to save several files in a row.

Is my CSV uploaded to a server?

No. The file is read and split entirely in your browser using JavaScript. Nothing is transmitted or stored, so large exports containing private data are safe to split here.

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