CSV Splitter
A 500,000-row CSV doesn't fit in most tools. Split it into equally sized chunks, or divide it by the values in a key column — each output file gets its own header and can be downloaded as a ZIP.
CSV Splitter
Split large CSV into multiple smaller files by row count, file size, or column value groups
Drag and drop a CSV file here, or click to browse
or paste CSV data below
How CSV Splitter Works:
- By Row Count: Split into files with N rows each
- By File Size: Split into files of maximum size
- By Column Value: Group rows by unique column values
- Headers can be included in each split file
- Download individual files or all at once
What This Tool Does
This tool splits a large CSV file into multiple smaller CSV files. Choose to split by row count (e.g., 1000 rows per file), by file size (e.g., 5MB per file), or by unique column values (e.g., one file per country). Each output file includes headers.
Split Modes
By row count: Specify how many rows per file. A 10,000 row file split into 1,000 rows creates 10 output files.
By file size: Specify maximum file size in KB or MB. The tool calculates how many rows fit within the limit.
By column value groups: Each unique value in a column gets its own file. Useful for splitting by category, region, or date.
Headers in each file: All output files include the header row for standalone usability.
Example: Split by Row Count
Input: 5,000 rows
Split by: 1,000 rows per file
Output files:
output_part_1.csv - 1,000 rows output_part_2.csv - 1,000 rows output_part_3.csv - 1,000 rows output_part_4.csv - 1,000 rows output_part_5.csv - 1,000 rows
Example: Split by Column Value
Input CSV:
id,name,country 1,Alice,USA 2,Bob,UK 3,Charlie,USA 4,Diana,Canada 5,Eve,UK
Split by: country column
Output files:
country_USA.csv: id,name,country 1,Alice,USA 3,Charlie,USA country_UK.csv: id,name,country 2,Bob,UK 5,Eve,UK country_Canada.csv: id,name,country 4,Diana,Canada
When to Use This
Email campaign batches: Split large contact lists into smaller files for email service providers with batch limits.
API upload limits: Many APIs have file size or row count limits. Split data to fit within constraints.
Parallel processing: Split data for parallel processing across multiple workers or machines.
Regional distribution: Split customer data by country or region for local teams.
Manageable chunks: Break large files into smaller pieces that Excel or other tools can handle.
File Naming
Output files are named automatically:
Row count mode: filename_part_1.csv, filename_part_2.csv, etc.
Size mode: filename_part_1.csv, filename_part_2.csv, etc.
Column value mode: filename_value1.csv, filename_value2.csv, etc. (e.g., country_USA.csv)
Download Options
Individual download: Download each split file separately.
Batch download: Download all files as a ZIP archive (if supported by your browser).
Limitations
Large files: While splitting helps manage large files, the input file still loads into browser memory. Files over 200MB may cause issues.
Many output files: Splitting by column value with many unique values creates many files. 1,000 unique values = 1,000 output files.
File size estimation: Size-based splitting is approximate. Actual file sizes may vary slightly.
Frequently Asked Questions
Do output files include headers?
Yes. Every output file includes the header row, making each file independently usable.
Can I customize the output file names?
This tool uses automatic naming. For custom names, rename files after download or use a script.
What happens if the last chunk is smaller?
The last file contains remaining rows. If splitting 5,500 rows into 1,000-row chunks, the last file has 500 rows.
Other Free Tools
CSV File Merger
Monthly exports, regional data splits, batch outputs — merge them all into one clean CSV. Handles mismatched column sets intelligently and optionally tags each row with its source file.
CSV Column Splitter
Full names jammed into one column? Addresses that should be five fields? Split any column into as many parts as you need using delimiters, regex, or fixed positions — no formulas, no fuss.
CSV Join / Merge Tool
Join two CSV files on a shared key column — just like a SQL JOIN, but without a database. Inner, left, right, or full outer join — pick your type, map your key columns, and get a merged file instantly.
CSV Cleaner
Trailing spaces, blank rows, BOM markers, Windows line endings — the tedious stuff that breaks imports and wastes your time. Run it through our cleaner and get a corrected file with a full report of what changed.
CSV Row Filter
Extract exactly the rows you care about using intuitive conditions — filter by value, range, pattern, or date across any column. Combine rules with AND/OR logic and download the matching subset in seconds.