csv-diff

compare CSV files and show differences

TLDR

Diff two CSV files

$ csv-diff [old.csv] [new.csv]

Diff with specific key column

$ csv-diff [old.csv] [new.csv] --key [id]

Output as JSON

$ csv-diff [old.csv] [new.csv] --json

Show only changes

$ csv-diff [old.csv] [new.csv] --show-unchanged

SYNOPSIS

csv-diff [options] old.csv new.csv

csv-diff compares two CSV, TSV, or JSON files and shows added, removed, and changed rows. It's useful for tracking changes in data exports, database dumps, or any tabular data.A --key column must be specified so rows can be matched across files. Output is human-readable by default, and machine-readable JSON is available via --json.The tool is a standalone Python package by Simon Willison, installable via `pip install csv-diff`. It is distinct from csvkit.

PARAMETERS

--key column

Column to use as unique identifier.

--json

Output in JSON format.

--show-unchanged

Include unchanged rows in output.

--singular name

Singular noun for rows.

--plural name

Plural noun for rows.

CAVEATS

Rows without a stable unique key cannot be meaningfully compared; choose a column guaranteed to be present on both sides. Large files are loaded fully into memory.