CSV Diff

Compare two CSV files to identify changes, additions, or deletions between them and generate a unified diff output similar to git diff.

When to use

Use this when you need to:

• Compare two CSV files and see what changed between them, especially for large datasets.
• Generate a unified diff file for tracking changes in tabular data.

Quick start

Compare two CSV files:

csvdiff old.csv new.csv

This will generate a result.diff file showing the differences.

Documentation

• Run csvdiff --help to see available options and usage.
• Read the documentation for more details.

Output

The tool generates a unified diff output similar to the following:

--- old.csv
+++ new.csv
@@ -2,3 +2,3 @@
 0,Alice,70000
-1,John,50000
+1,John,55000
 2,Jane,60000

The output shows:

• Lines prefixed with - were removed or changed
• Lines prefixed with + were added or changed
• Context lines (no prefix) show unchanged data for reference

Notes

• CSV files must have a header row.
• Output is saved to a .diff file (default: result.diff).

Requirements

The csv-diff-py package must be installed in your environment. You can install it globally via uv (or user-preferred python package manager):

uv tool install csv-diff-py

Alternatively, run it directly with uvx (or user-preferred python package runner):

uvx --from csv-diff-py csvdiff file1.csv file2.csv