When you receive a CSV you usually want a quick sense of each column before doing anything with it: what range the numbers span, where the average sits, and how many cells are empty. This CSV column statistics tool parses your file and produces per-column summaries in your browser, with a small histogram for the numeric columns.
How it works
The tool first parses the CSV with a quote-aware RFC 4180 parser, so quoted fields that contain commas, newlines, or doubled quotes are handled correctly instead of naively splitting on commas. You choose the delimiter and whether the first row is a header.
For each column it counts non-empty and empty cells. If every non-empty cell is numeric it computes:
- minimum and maximum,
- mean (arithmetic average),
- median (middle value, or the average of the two middle values),
- population standard deviation, the square root of the average squared deviation from the mean,
- a ten-bin histogram rendered as a sparkline.
Columns with any non-numeric value are summarised instead by their count of distinct values and a few sample entries.
Example
In the sample, the score column has one empty cell, so its null count is 1, and its statistics are computed over the remaining numeric values. The city column is text, so it reports the number of distinct cities and a list of samples rather than a mean.
Notes
The reported standard deviation is the population value; if you specifically need the sample standard deviation, apply Bessel’s correction. Treat the histogram as a quick shape check rather than a precise distribution plot. Everything runs locally, so even confidential CSVs stay on your device.