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CSV Splitter

Split a CSV into smaller parts of N rows each, in your browser. Every part repeats the header, shown together in one output to copy out.

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Quick Answer

Paste a CSV with a header row and choose how many rows per part. The tool divides the data rows into chunks of that size and repeats the header on each one. All the parts appear in a single output box, separated by clear part markers, ready for you to copy out. It runs in your browser.

What the CSV Splitter Does

This breaks a large CSV into smaller pieces. You set the number of rows per part, and the tool splits the data rows into chunks of that size, repeating the header row at the top of each part so every piece is a valid CSV on its own.

All the parts are shown together in one output, each introduced by a part marker. You copy each part out yourself — the tool does not download separate files.

How It Works

Paste your CSV, including the header row, and set the rows-per-part number.

The header is kept aside, and the data rows are divided into chunks of your chosen size.

Each chunk is rebuilt as a CSV with the header on top, labelled with a part marker, and all parts are shown in one box to copy. It runs in your browser.

Data source & conversion logic

  1. Parse the CSV. The text is parsed into a header row and the data rows.
  2. Chunk the rows. The data rows are divided into groups of the size you choose.
  3. Rebuild each part. Each group becomes a CSV with the header repeated and a part marker.
  4. Show all parts. The parts appear together in one output box to copy out.

How the split works

Header row is kept and repeated in every part Each part = the header + up to N data rows (N = rows per part) Parts are shown together, separated by part markers Number of parts = data rows divided by N, rounded up
Worked example
A CSV with 5 data rows split at 2 per part gives 3 parts — two of 2 rows and one of 1 — each starting with the header and a part marker.

Everything appears in one output box; copy each part out yourself. The tool does not download separate files.

Privacy

Your CSV is processed entirely in your browser — there is no server and nothing is uploaded.

The data never leaves your device, so even sensitive records stay private.

No account, no stored copy; the conversion is gone when you close the tab.

Technical Details

InputCSV with header row
ControlRows per part (min 1)
HeaderRepeated in each part
OutputAll parts in one box
SeparatorsPart markers
FilesNot downloaded separately
Processing100% in-browser

Standards & references

  • RFC 4180 (CSV) — The parser understands quoted fields and doubled quotes, so a value with a comma stays intact when split.
  • Header-per-part — Repeating the header on each part keeps every piece a self-contained, valid CSV.

Accuracy & Limitations

The parts are shown together in one output box, not downloaded as separate files. Copy each part, between the markers, into its own file yourself.

The header row is repeated on every part, so each piece opens correctly on its own. Your first row must be the header.

Rows per part is at least one. The last part holds whatever rows remain, so it may be smaller than the others.

The parser handles quoted fields, so a value containing a comma or a line break is kept whole and counted as one row.

Real-World Use Cases

Beat an import limit

Split a big CSV into parts small enough for a tool that caps rows per upload.

Share in pieces

Break a long CSV into manageable chunks to send or review.

Batch processing

Divide data into parts you can process one at a time.

Sample a file

Grab just the first part as a quick sample of a large CSV.

When to use it — and when not to

Good for

  • Breaking a CSV into fixed-size row chunks
  • Keeping a valid header on each piece
  • Quick manual splitting you copy out

Not the best choice for

  • Automatic download of many separate files
  • Splitting by a column value rather than row count
  • Files too large to paste into the box

If you need each part as its own downloaded file, copy each marked part into a new file yourself, or use a desktop CSV splitter. To split an Excel workbook by sheet, use the Excel sheet splitter.

Frequently Asked Questions

Does it download separate files?
No. All parts appear in one output box, separated by markers. Copy each part out into its own file yourself.
Is the header repeated?
Yes. The header row is placed at the top of every part, so each piece is a valid CSV on its own.
How do I set the part size?
With the rows-per-part control. The minimum is one row per part.
What is in the last part?
Whatever rows remain after the full-size parts, so the last part can be smaller.
Does my first row need to be the header?
Yes. The first row is treated as the header and repeated on each part.
Does it handle quoted fields?
Yes. A value containing a comma stays in one field and counts as a single row when splitting.
Can I split by a column value?
No. It splits purely by row count, not by the contents of a column.
How many parts will I get?
The number of data rows divided by your rows-per-part, rounded up.
What are the part marker lines?
They are labels that separate the parts in the output. Remove the marker line when you copy a part into its own file.
Is my data uploaded?
No. The split runs entirely in your browser.
Is there a size limit?
Only what your browser can hold in the text box; very large files may be slow.
How do I recombine parts?
Use the CSV merger to stack them back into one file.

References

Parses your CSV and divides the data rows into parts of the size you choose, repeating the header on each part. The parts appear together in one output box, separated by part markers, for you to copy out — it does not download separate files. Runs in your browser.

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