About the CSV Splitter
Large CSV files can be too big for a spreadsheet, an email attachment or an import form that limits the number of rows. This splitter cuts a CSV into several smaller files. Decide how many data rows each file should hold, keep the header in every part if you want, and the tool shows the parts one after another with their file names. A button downloads all of them as a ZIP, so you do not have to save each one separately. Quoted values and line breaks inside cells are respected, and the work is done in your browser.
Updated October 2026
How to use the CSV Splitter
- 1Paste your CSV into the box.
- 2Enter how many data rows each file should hold.
- 3Keep the header option on to repeat the header row at the top of every part.
- 4Check the list of parts and their row counts.
- 5Press Download ZIP to save all parts, or copy the text.
When to split a CSV
Excel stops at 1,048,576 rows, many web forms cap uploads at a few thousand rows, and email services limit attachment size. Splitting turns one unmanageable file into several that each fit. It is also useful for sharing work between people, with each person getting one part, or for running a slow process on batches.
Keep the header in each part so that every file stands alone. Turn it off only if you will join the parts again later with the header from the first.
Choosing the number of rows
Check the limit of the place you are importing to, then set the row count a little below it. For a 5,000-row limit, 4,500 rows per file leaves room. If you want a certain number of parts instead, divide the total rows by that number and round up.
- Spreadsheet comfort: 50,000 rows
- Web import form: 1,000 to 5,000 rows
- Email attachments: depends on the size limit
After the split
The ZIP contains the parts in order. Open the first and last to check the header and the final rows. Total rows across all parts should equal the total in the original; the note under the box shows both.
Naming of the parts
Each part gets its own file name in the ZIP, numbered in the order of the original rows. The text view shows a line with the name and row count before each part so you can check them without unzipping.
Keep the ZIP together with the original file until you have confirmed that every part imported correctly. A split file is often just the start. Check a single field in each part with CSV Column Extractor, remove repeated rows from a part with Remove Duplicate Lines, and use CSV Tools for sorting or merging the parts again later.
Features
- Split by number of data rows
- Repeats the header row in each part
- Download all parts as a ZIP
- Quoted cells with line breaks stay whole
- Shows the row count of every part
- Private: nothing is uploaded
Frequently asked questions
How do I split a CSV into smaller files?
Paste the CSV, set the number of rows per file and press Download ZIP. The ZIP holds numbered files such as part-1 and part-2, each with the rows you asked for.
Will each part have the header row?
Yes, when the header option is on. The first row of your CSV is copied to the top of every part, so each file can be imported by itself.
Does the row count include the header?
No. The number you enter is the count of data rows. A 1,000-row limit with the header repeated gives files of 1,000 data rows plus the header line.
What if a cell contains a line break?
The tool reads quoted cells properly, so a line break inside quotes does not start a new row and a part never cuts through a cell.
How big a file can I split?
The tool accepts a very large paste, but a phone browser may slow down with millions of characters. For the largest files, use a computer.
Is my data uploaded?
No. The splitting and the ZIP are made in your browser. Nothing is sent to a server.