Transpose CSV Files Online
Transpose CSV files — flip rows and columns — directly in your browser. No upload, no server.
About this tool
Flip the rows and columns of a CSV file — turn a wide dataset into a long one or vice versa. Useful when preparing data for charting libraries, pivot tables, or analytics tools that expect a specific orientation.
Frequently Asked Questions
What does transposing a CSV file do?
Rows become columns and columns become rows. A file with 5 columns and 100 rows produces a transposed file with 100 columns and 5 rows.
How are column names handled when transposing a CSV file?
The original column names become values in the first column of the output. The original row values become the new column headers.
When would I transpose a CSV file?
Transposing is useful when switching between wide format (many columns, few rows) and long format (few columns, many rows) — a common step when preparing data for charting, pivot tables, or certain analytics tools.
Is my data private?
Yes — completely. Your file is never uploaded to any server. Everything runs locally in your browser using WebAssembly — processing happens entirely inside your tab. Once you close the tab, nothing is retained.
What is the maximum file size?
The free limit is 50 MB. For larger files, performance depends on your device's available memory — most modern machines handle 500 MB to 1 GB comfortably.
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