Compare two CSV files online
Drop two .csv files and get a diff in seconds — every added row, removed row, and modified value highlighted. 100% private. Your files never leave your browser.
Original file
Drag & drop or browse
XLSX, XLS, CSV
New version
Drag & drop or browse
XLSX, XLS, CSV
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How to compare two CSV files
- Drop both files
Load your "before" CSV on the left and "after" CSV on the right. .csv, .xlsx, and .xls all work.
- Review the diff instantly
Added rows are highlighted green, removed rows red, modified cells yellow. Use the search and filter bar to zero in on specific changes.
- Export the result
Download an annotated .xlsx or HTML report — or use Reconcile mode to produce a merged output file.
Frequently asked questions
- How do I compare two CSV files?
- Drop both files above. SheetToolkit highlights every added row (green), removed row (red), and modified cell (yellow). Use the filter bar to isolate specific change types. Nothing is uploaded — all processing runs in your browser.
- Can I compare CSV files with different column orders?
- Yes. SheetToolkit aligns columns by header name, not position — so reordered columns are matched correctly. If a header was renamed between files, use the Advanced → Column mapping option to tell the tool which columns correspond.
- Does it work with large CSV files?
- Free users can compare files up to 5,000 rows. SheetToolkit Pro removes all row limits with a one-time payment — no subscription.
- What's the difference between comparing CSV and Excel files?
- SheetToolkit handles both formats with the same engine. CSVs are single-sheet files by definition; Excel files can have multiple sheets (Pro feature unlocks multi-sheet comparison).
- Can I compare a CSV against an Excel file?
- Yes. Mix and match formats freely — load a .csv on one side and a .xlsx on the other. SheetToolkit reads both and diffs the data.
- Is my data private?
- Completely. Files are processed entirely in your browser using JavaScript. Nothing is ever sent to any server. You can disconnect from the internet after the page loads and the tool still works.