CSV Difference Analyzer (Diff Tool)

Compare two CSV files (Base and New) to find added, deleted, and modified rows.

Comparison Setup

File A (Base Data)

File B (New Data)

Primary Key Column (Unique ID)

Must be present in both files.

Difference Report

-- Load File A (Base) and File B (New) and select a Primary Key column to begin analysis.

About This Tool

The CSV Difference Analyzer lets you compare two CSV datasets to detect any changes between them. It highlights added, deleted, modified, and unchanged rows by matching records using a Primary Key column. All operations are performed entirely in your browser, ensuring full privacy and fast performance even with large files.

Key Features:

Private Processing: Files never leave your device.
Primary Key Matching: Accurately aligns rows from both CSV files.
Detailed Diff Classification: Labels rows as Added, Deleted, Modified, or Unchanged.
Column-Aware Comparison: Automatically compares all shared and unique columns.
Preview Output: Shows a formatted preview of the first 20 difference rows.
Exportable Report: Download the full difference dataset as a CSV file.

How to Use

Load Files: Select File A (base data) and File B (new data). Both will be parsed automatically.
Select Primary Key: Choose a column that uniquely identifies each row in both files.
Run Comparison: Click Run Comparison to detect added, deleted, and modified rows.
Review Results: View a preview of the difference output in the console panel.
Export Diff: Click Export Diff CSV to download the full difference report.