Excel & CSV Data Comparator
Compare File A and File B to generate unique reports and a combined Difference File (Part C).
Advanced Data Comparison: Excel & CSV Diff Tool
In data management, identifying changes between two datasets is a frequent necessity. Whether you are auditing financial records, updating product inventories, or cleaning mailing lists, manually spotting differences between thousands of rows is impossible. Our Excel & CSV Comparator automates this logic entirely.
How This Tool Logic Works
This tool treats your files as sets of data and performs the following operations:
1. Unique to A
Rows present in the Old File (A) but missing in the New File (B). These represent deleted or lost items.
2. Unique to B
Rows present in the New File (B) but missing in the Old File (A). These represent new additions.
3. Part C (Combined)
This is the "Symmetric Difference". It combines Unique A and Unique B into a single file, showing EVERYTHING that is different.
Why Generate "Part C"?
Most comparison tools only show you what matched. However, for analysts and developers, the Differences (Part C) are usually more important. Part C allows you to:
- Reconcile Data: See exactly what doesn't match between two system exports.
- Audit Logs: Create a report of everything that changed (Added + Removed) in a single document.
- Migration Checking: Verify that data transfer didn't lose or incorrectly add records.
Frequently Asked Questions (FAQ)
Yes! Unlike many free tools, our processor supports both .csv and Excel formats (.xlsx, .xls). The tool automatically converts Excel data to a readable format in your browser before comparing.
Part C is a merged file. We take all the rows that are unique to File A and all the rows unique to File B, and combine them into one dataset. This gives you a complete view of all discrepancies.
Yes. For a row to be considered "Identical", every column value must match exactly. If column A in one file corresponds to column B in another, please rearrange them in Excel before uploading.
Absolutely. This tool runs Client-Side Only. Your Excel/CSV files are processed by your own web browser's JavaScript engine. No data is ever uploaded to our servers or stored anywhere.