CSV Key Diff: Compare Rows by Primary Key
Compare local CSV files by a single or composite key, ignoring row and column order while identifying exact string changes.
Enabling local controls…
1. Add two CSV files
Data stays in this browser. No upload, storage or tool analytics events.
Each UTF-8 file: up to 5 MiB, 20,000 rows, 100,000 cells including headers, and 200 columns. Header name sets must match; column and row order may differ.
2. Keys and differences
Paste two sources or load the sample, then press Parse.
How to use this tool
Parse two UTF-8 CSV inputs with the same column names, choose unique key columns and compare. Inspect added, removed and modified records; download the complete JSON report after reviewing its sensitive values.
When not to use it
No fuzzy matching, automatic key inference or schema migration. Duplicate keys block comparison. Whitespace and case are significant; the JSON report includes original values and is not anonymized.
Read the guide →