What Turbo Large Data Splitter Does
Turbo Large Data Splitter is a Windows tool built to split csv into multiple files, split Excel files into multiple files, and merge them back together again, all without the row limits and memory problems that come with opening huge files in Excel or a spreadsheet app. It can split CSV, TSV, TXT, XLSX, XLS, JSON, XML, and SQL dump files, and it can convert formats while splitting - for example, splitting one giant CSV file into several smaller XLSX files. Every file is read and written in a single streaming pass, so multi-gigabyte and 100 GB+ files are supported as long as there is enough free disk space for the output.
Supported Input Formats
SQL dump files are read line by line, so each line in the dump is treated as one row when splitting.
Supported Output Formats
Input format and output format are independent settings, so converting CSV to XLSX, XLSX to CSV, JSON to CSV, and similar combinations all work in the same pass as the split or merge.
Key Features
▶ Split CSV and Excel Files Into Multiple Files
Split csv into multiple files, or split Excel file into multiple files, using whichever method fits your data: number of rows, target file size, a column's value, a date column, alphabet ranges, duplicates, or unique values. Everything streams row by row, so splitting a large CSV into multiple files never depends on how much memory your PC has.
▶ Merge and Combine Files Back Into One
The Merge tab works as a csv merger and csv combiner: add the part files in the order you want them joined, and Turbo Large Data Splitter writes the header once and appends every row after it. Choose the XLSX output format to merge csv files into one Excel workbook, or merge xlsx files into one workbook directly.
Split by Number of Rows
Every output part gets the same number of rows - for example, 1,000,000 rows per file - which is the most common way to split a csv file into multiple files for import into another system.
Split by File Size
Rolls over to a new part whenever the current file reaches your target size in megabytes, keeping every output file under a size limit you set.
Split Excel File by Column Value
Writes one output file per distinct value found in a chosen column - for example, one file per Country or one file per Department - a direct way to split an Excel file into multiple files by column value.
Split Excel File Into Multiple Files by Row
Set the split method to Number of Rows to split excel file into multiple files by row, removing the roughly 1,048,576-row-per-sheet ceiling that Excel itself imposes on a single worksheet.
Split by Date Column
Groups rows by day, month, or year based on a date column, which is useful for splitting transaction logs, order histories, or sensor data into monthly or yearly files.
Alphabet Range Splitting
Buckets rows into ranges such as A-F, G-L, M-R, S-Z, 0-9, and Other, based on the first letter of a chosen column, for name-sorted or catalog-style datasets.
Duplicate and Unique Value Splitting
Splits rows into a duplicates file and a first-seen file, or keeps only the first occurrence of every row and drops the rest - handy for cleaning a file before splitting or merging it.
Multi-Sheet Excel Support
When an XLSX file has more than one sheet, choose the largest sheet automatically, always use the first sheet, or pick an exact sheet name - the same choice is available when you merge xlsx files into one workbook.
Advanced CSV / TSV / TXT Settings
Set the delimiter, text encoding, and whether the first row is a header. Sort rows by a column using a disk-based merge sort that works on huge files, filter rows with a simple expression, and remove exact duplicate rows before splitting.
Compression Options
Leave output parts as plain files, or compress each one individually with ZIP or GZIP, or bundle every part into a single ZIP archive or a single GZIP tarball for easier sharing.
Parallel Compression Workers
Reading and splitting happens in one ordered pass to keep row order correct, but compressing the finished parts can run in parallel - up to 128 workers - for jobs that produce many output files.
Resume Interrupted Jobs
If a split job is cancelled, closed, or interrupted partway through, a checkpoint is saved automatically. Running the exact same job again picks up right where it left off instead of starting over.
Drag and Drop, Recent Files
Drag a file straight onto the app window, or pick it from a list of recently used files. A live preview shows the total row count, detected columns, and an estimate of how many output files you'll get before you start.
Split Methods Explained
| Method | What It Does |
|---|---|
| Number of Rows | Every output part gets the same number of rows (up to 1,000,000 rows per file). |
| File Size | Starts a new part once the current one reaches your target size in MB. |
| Column Value | Writes one output file per distinct value in a chosen column. |
| Date Column | Groups rows by day, month, or year based on a date column. |
| Alphabet Ranges | Buckets rows into A-F, G-L, M-R, S-Z, 0-9, and Other, based on a column's first letter. |
| Duplicate Values | Splits rows into a "duplicates" file and a "first seen" file. |
| Unique Values | Keeps only the first occurrence of each row and drops later duplicates. |
Safety and Reliability
- Streaming Architecture - Reads and writes files row by row instead of loading everything into memory, so multi-gigabyte files split and merge reliably.
- Automatic Checkpointing - A cancelled or interrupted split job resumes from where it stopped instead of starting from scratch.
- Format-Safe Merging - The Merge tab flags any file whose extension does not match the chosen format before combining, to prevent a mixed-format merge from failing partway through.
- Header Handled Once - When merging, the header row from the first file is written once and never repeated in the combined output.
- Disk-Based Sorting - Sorting rows by column before splitting uses a merge-sort on disk, so it does not run out of memory on very large files.
- Ideal for Sensitive Environments - Corporate offices, data teams, and air-gapped networks that cannot send data files to an online tool.
Performance and Speed
Single Streaming Pass
Reading and splitting happens in one continuous, ordered pass, which keeps row order correct and makes resuming an interrupted job possible.
Up to 128 Parallel Workers
Compression of finished output parts can run with up to 128 parallel workers, which speeds up jobs that produce many ZIP or GZIP files.
Handles 100 GB+ Files
Since files are streamed rather than loaded fully into memory, the practical limit is free disk space rather than RAM.
Fast XLSX Reading
Excel files are read with a high-speed engine, which keeps large XLSX-to-CSV and XLSX-to-XLSX splits quick even with hundreds of thousands of rows.
Security and Privacy
Turbo Large Data Splitter is a fully local desktop application. All splitting, merging, sorting, and filtering happen on your own computer. No files are uploaded, scanned remotely, or shared with third parties, which makes it a dependable alternative for anyone who searched for a csv splitter online or a csv merge online tool but needs to keep sensitive data on their own PC.
- Does not upload, log, or store your data files
- No file-size cap imposed by a server, unlike most online tools
- Internet is used only for license validation - the request contains no file names or file content
- Suitable for financial records, customer data, and other confidential datasets
Minimum System Requirements
| Operating System | Windows 8 (64-bit) |
| Processor | 1-2 CPU cores |
| Memory | 4 GB RAM |
| Storage | Free disk space at least equal to the size of the input file |
Recommended System Requirements
| Operating System | Windows 10 or later (64-bit) |
| Processor | 4 or more CPU cores |
| Memory | 8 GB RAM or more |
| Storage Type | SSD recommended for the fastest split and merge speeds |
| Free Disk Space | At least twice the size of the input file, for output and checkpoint files |
App Info
| App Name | Turbo Large Data Splitter |
| Platform | Windows |
| Category | Data File Tools |
| License Management | Gumroad |
Supported Conversions While Splitting
| CSV | → | TSV, TXT, XLSX, JSON, XML |
| TSV | → | CSV, TXT, XLSX, JSON, XML |
| TXT | → | CSV, TSV, XLSX, JSON, XML |
| XLSX | → | CSV, TSV, TXT, JSON, XML |
| XLS | → | CSV, TSV, TXT, XLSX, JSON, XML |
| JSON | → | CSV, TSV, TXT, XLSX, XML |
| XML | → | CSV, TSV, TXT, XLSX, JSON |
| SQL | → | CSV, TSV, TXT, XLSX, JSON, XML |
A Reliable CSV Splitter and CSV Merger for Large Files on Windows
Turbo Large Data Splitter is a dedicated csv splitter for Windows built for the moment a spreadsheet gets too big to open. Whether you need to split csv into multiple files for a database import, split csv file into multiple files windows-side before emailing them, or split an Excel file into multiple files by row or by column value for separate teams, the app streams each file instead of loading it whole, so it stays fast and stable well past the point where Excel itself would refuse to open the file. If you have been searching for a way to split csv into multiple files online, or looking for a csv splitter online or a csv split online service, it is worth knowing why the Windows download usually works better for large files: an online tool has to upload your data first, and most impose a file-size limit long before a real-world export gets interesting, while this csv splitter download runs entirely on your own PC with no upload step and no file-size ceiling of its own. The same app doubles as a csv merger and csv combiner - use the Merge tab to merge csv files into one file, merge csv files into one Excel workbook, or merge xlsx files into one workbook, picking up right where a split left off. For very large exports specifically, take a look at Million by Million Rows Copier, a companion TurboSoft tool built for copying tens of millions of rows between spreadsheets. And if the files you are working with are images rather than data, Turbo Batch Image Converter Pro handles batch image conversion and resizing with the same offline, no-upload approach.
Frequently Asked Questions
How to split CSV into multiple files on Windows?
Open Turbo Large Data Splitter, browse to your CSV file or drag and drop it in, pick an output folder, choose a split method such as Number of Rows or File Size, then click Start Split. The app streams the file row by row, so it works as a reliable csv splitter for Windows even on multi-gigabyte files.
How to split a large CSV into multiple files without running out of memory?
Turbo Large Data Splitter never loads the whole file into memory - it reads and writes in a single streaming pass, so splitting a large CSV into multiple files only needs enough free disk space, not enough RAM. Jobs also checkpoint automatically, so an interrupted split can resume instead of starting over.
Can I split an Excel file into multiple files by row?
Yes. Choose Number of Rows as the split method and set how many rows each part should contain. This is a common way to split an Excel file into multiple files by row, and it also removes Excel's 1,048,576-row-per-sheet limit, since each part becomes its own workbook.
Can I split an Excel file into multiple files by column value?
Yes. Select Column Value as the split method and choose the column to group by, such as Country or Department. Turbo Large Data Splitter then writes one output file for every distinct value found in that column.
Is there a CSV splitter online, or only a Windows download?
Turbo Large Data Splitter is a Windows download rather than a csv splitter online tool, and that is by design: an online csv split tool has to upload your file to a server first, which is slow and often capped at a small file size. The Windows version processes everything locally, so there is no upload step and no practical size limit.
Can I merge CSV files into one, or combine them into a single Excel workbook?
Yes. The Merge tab works as a csv combiner and csv merger: add the part files in order, choose an output format, and the app writes the header once and appends every row after it. Set the output format to XLSX to merge csv files into one Excel workbook instead of a plain CSV.
Can I merge multiple XLSX files into one workbook?
Yes. Set Format to xlsx on the Merge tab, add the XLSX files you want combined, and choose whether each file's largest sheet or first sheet should be used. Turbo Large Data Splitter will merge xlsx files into one workbook, in the order you added them.
Is there a CSV merge online tool?
Turbo Large Data Splitter's Merge tab covers the same job a csv merge online tool would, but without the upload step or the file-size limits that online tools tend to enforce, since the merge runs locally on your PC.
Where can I get the CSV splitter download?
Click Buy Now above to purchase a license through Gumroad, or Download Demo to try Turbo Large Data Splitter before buying. Activation only needs the purchase email and license key shown on the Gumroad receipt.