CSV Difference Explainer — Private Offline Audit Tool

Two exports look almost the same. Almost is the troublesome part.

CSV Difference Explainer turns an earlier and later CSV into a small, reviewable audit:

• records added, removed, or changed;

• cell-by-cell changes;

• columns added or removed;

• dominant value-type shifts;

• duplicate keys and exact duplicate rows;

• blank values and mixed types;

• explicit warnings when a comparison is ambiguous.

Choose a matching key such as id, sku, or email, then inspect the result in your browser. Save a standalone HTML audit or focused CSV tables for row changes, cell changes, and quality signals.

Everything runs in one local HTML file. There are no uploads, analytics, remote libraries, accounts, subscriptions, or installation steps. Your data stays on your device unless you decide to share an exported report.

Included: offline HTML app, two sample CSV files, quick start, documentation, license, and AI/data-use disclosure.

Best for: operations teams, researchers, analysts, freelancers, QA reviewers, migration checks, vendor-export reviews, and anyone asking “what actually changed?”

Deliberate boundaries: CSV/TSV only; no fuzzy entity matching; no automatic repair; no compliance certification; recommended for files up to about 100,000 rows or 25 MB per file depending on device.

Support covers opening the included file and reproducing a defect with the included sample data in a current desktop browser. It does not include custom formats, data cleaning, fuzzy matching, consulting, file recovery, compliance review, or analysis of confidential customer datasets. Do not email sensitive data.