Summarize CSV by Group, free in your browser

Group CSV or TSV rows by one selected column and calculate a row count or numeric sum, average, minimum, or maximum for each group.

How to summarize CSV rows by group

Choose a CSV or TSV file.
Choose the group column and calculation; for numeric calculations, choose a numeric column.
Create and download the summary CSV.

Files up to 50 MB, 500,000 rows, and 2,000 columns are processed on your device.
Numeric calculations skip blank cells and stop with a clear error if a non-empty value is not numeric.
Group names are kept in their first-seen order; output values are plain CSV text.

Are my files uploaded to a server?: Your files are processed on your device, not uploaded to our servers. Your file and edits are saved in this browser for recovery, and previous documents remain in Saved drafts when you open another file. Use Saved drafts to resume or delete individual copies, or clear this site’s browser data to remove all copies. Browser storage can be cleared or become unavailable; download important work.
How are blank numeric values handled?: Blank cells are excluded from sum, average, minimum, and maximum calculations. Count rows counts all records in each group.
Is this really free, or free "until you hit a limit"?: Really free. Unlike most "free" PDF sites there is no task-per-day cap, no locked Pro features, no watermark stamped on your file, and no payment step before download. Every tool is the full tool.