Split & clean CSV, TSV & XLSX
in seconds — free, private, forever

Split by size, rows, file count, or column value. Preview data before splitting. Filter columns, download as ZIP. Works entirely in your browser.

No file upload ever
CSV · TSV · XLSX
Download as ZIP
Data preview
Works offline

Drop your file here

CSV TSV XLSX / XLS
Your file stays on your device — never uploaded
Rows
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Columns
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File size
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Parsed in
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Select multiple CSV, TSV or XLSX files to merge into one. All files must have the same columns.

Output format

Merging…

Convert between CSV, TSV and XLSX formats without splitting.

Drop file to convert

CSV TSV XLSX

How to split large CSV, TSV & Excel files

Perfect for Salesforce, HubSpot, Zoho, Mailchimp, and any CRM with upload size limits.

Step 1

Upload your file

Drop or browse any CSV, TSV, or Excel XLSX file. Processed 100% in your browser — nothing uploaded.

Step 2

Preview & filter columns

See the first 10 rows instantly. Search and uncheck columns you don't need in the output.

Step 3

Choose split mode

Split by file size (CRM presets), row count, number of files, or by a column's unique values.

Step 4

Download as ZIP

Get all output files in one ZIP download. Or download CSV, TSV, or XLSX individually.

Frequently asked questions

No. SplitCSV runs entirely in your browser using JavaScript. Your file is never uploaded to any server, never stored, and never transmitted. This makes it safe for customer data, PII, or any confidential business files.
Yes. SplitCSV now supports Excel .xlsx and .xls files natively. Drop your Excel file and it will be read automatically. You can also output split files as XLSX if you prefer.
Yes. With the "Download as ZIP" option enabled (the default), all output files are bundled into a single ZIP archive you can download in one click. This avoids browser popup blocking that happens with sequential downloads.
There is no hard limit — it depends on your device's available RAM. Files up to 200–300 MB work smoothly on most computers. Files up to 500 MB are possible on machines with 8 GB+ RAM. For very large files, use Chrome or Edge on a desktop.
Select "By file size" and click the "Salesforce / HubSpot — 25 MB" preset. SplitCSV splits your file into chunks under 25 MB, ready to upload one by one.
Yes! Use the "Merge files" tab to combine multiple CSV, TSV, or XLSX files into one. All files should share the same column headers. You can optionally remove duplicate rows during the merge.
Four modes: (1) By file size — each output file stays under a chosen MB/KB limit. (2) By row count — fixed rows per file. (3) By file count — rows distributed evenly. (4) By column value — one file per unique value in a chosen column (great for region or status splitting).