Your files never leave this device — 100% in-browser

Split CSV Into Smaller Files

Break a giant CSV into Excel-friendly parts — the header repeats in every file, and everything happens on your device with no size cap.

Set rows-per-file, drop your CSV, download one ZIP of numbered parts — each with the header repeated so it opens standalone in Excel. Splitting follows real record boundaries (quoted line breaks can't tear a row), and there's no size-based paywall because nothing uploads.

Last verified 2026-08-15 — this tool passed 79 automated end-to-end checks

rows per file
Drop a .csv file here, or click to browse
converts to split · header repeated per part · ZIP output
01 — NO SIZE PAYWALL
Server-based splitters upload your file and charge beyond a few hundred MB. Nothing uploads here, so there is nothing to meter.
02 — EXCEL-READY PARTS
Every part keeps the header row, a UTF-8 BOM and CRLF endings — each file opens standalone and correctly in Excel.
03 — CORRECT SPLITTING
A real RFC 4180 parser splits on rows, not lines — a line break inside a quoted cell never tears a record in half.

How to use

  1. Drop your file(s) into the box above — or click it to browse.
  2. Set rows-per-file first if 1,000 isn't right; splitting starts on drop.
  3. Click Download on each finished file — or Download all (.zip) for a batch. Nothing was uploaded at any point.

Why split a CSV at all?

Because the tools downstream have limits your export doesn't respect. Excel stops at 1,048,576 rows and gets sluggish long before that. Import screens for CRMs, email platforms and ad managers routinely cap uploads at 10k–50k rows or a few megabytes. And sharing a 400 MB export over email or chat is hopeless. The standard fix is the same everywhere: split by row count into parts, each with its own header so it opens as a valid standalone file.

Splitting behavior reference
Input situationResult
25,000 rows, 1,000 per file25 parts, each with the header row
Line break inside a quoted cellRecord stays intact in one part
Semicolon-delimited (European)Auto-detected, kept in output
EUC-KR / UTF-16 encoded fileConverted to UTF-8 with BOM
Output packagingOne ZIP: name-part01.csv, name-part02.csv…

The detail most splitters get wrong

A CSV row is not a line. Any quoted cell can legally contain line breaks — addresses, comments, product descriptions — and a naive line-based splitter will cut a record in the middle, corrupting that part and every part after it. This tool parses the file with the same RFC 4180 state machine as our CSV to JSON converter, so splits always land on real record boundaries. Semicolon and tab delimiters are auto-detected and preserved in the output, and legacy encodings (including EUC-KR) are converted to clean UTF-8.

Set the rows-per-file above (default 1,000), drop your file, and download one ZIP containing all parts, numbered in order.

When NOT to split

  • The destination accepts the whole file — databases and BI tools ingest millions of rows happily; splitting just adds bookkeeping.
  • You need cross-part analysis — pivot tables and deduplication want one dataset; split only for transport or import limits.
  • Multi-gigabyte exports — beyond browser memory (roughly the 25 MB-per-file guard here), use command-line tools like split + header stitching or xsv.

Frequently asked questions

Does every part have the header?

Yes — the first row of your file is repeated at the top of every part, so each one opens as a complete, valid CSV in Excel or any importer.

Is my data uploaded to split it?

No. Parsing, splitting and ZIP packaging all run in your browser. For customer data that must not touch third-party servers, that is the entire point.

What if my file has no header row?

The first row is treated as the header and repeated. If your data has no header, add one first — or note that part 1 will start with your first data row repeated in later parts.

Why one ZIP instead of many downloads?

Browsers make multi-file downloads awkward (pop-up blocking, click-per-file). A single ZIP with numbered parts is faster and keeps the set together.

Can I change how the values are quoted?

Values are re-quoted only when required (commas, quotes or line breaks inside a cell) and are otherwise preserved exactly as they appeared — splitting never rewrites your data.