Excel & CSV Diff Checker
Compare spreadsheets and huge datasets securely in your browser.
Find row-level differences between Excel (.xlsx) and CSV files. Optimized for large files with thousands of rows, ensuring speed and privacy without data uploads.
How to Compare Excel & CSV Files
Upload Spreadsheets
Drag and drop your 'Original' file into the left box and your 'Changed' file into the right box. We support .xlsx, .xls, and .csv formats.
Select Sheets
If your Excel file has multiple sheets, use the dropdown menu inside the upload box to select the specific sheet you want to compare.
Run Comparison
Click the 'Compare Spreadsheets' button. The tool will process rows and columns in your browser to find differences.
Review Data Changes
See row-by-row changes. Added rows are green, removed rows are red, and modified cells are highlighted in yellow with specific value changes shown.
Compare Large Data Sets Instantly
Spotting changed cells in a 10,000-row spreadsheet is nearly impossible with the naked eye. Standard text diff tools fail because CSV and Excel files are structured data, not just lines of text.
Diff Guru's Excel & CSV Compare Tool understands rows and columns. It intelligently detects inserted rows, removed data, and modified cells. Best of all, thanks to our advanced virtualization engine, you can scroll through massive datasets without your browser freezing.
Why use this tool?
Row-Aware Comparison
Detects inserted and deleted rows intelligently, keeping your data aligned.
Handles Large Files
Optimized for performance. Compare datasets with thousands of rows smoothly.
Format Support
Works with .xlsx, .xls, and .csv files out of the box.
Excel & CSV Diff FAQs
Yes. This is a purely client-side tool. Your Excel or CSV files are processed using JavaScript running in your own browser. The data is never uploaded to any server, making it safe for confidential business reports or financial statements.
The tool is optimized for performance and can comfortably handle files with tens of thousands of rows. The limit depends mostly on your computer's available RAM, as the entire file is loaded into browser memory.
It compares the calculated values of the cells. It does not compare the underlying formulas. This is usually what you want when checking for data discrepancies in reports.
Currently, the tool compares the first sheet of each workbook. Support for multi-sheet comparison is planned for a future update.
The tool currently compares based on column position (Column A vs Column A). If you reorder columns, it will register as a difference. We recommend sorting your columns similarly before comparison for the best results.