Compare Spreadsheet Data Online

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Compare Spreadsheet Data Online

Free online tool · No signup · Runs in your browser

Compare two CSV tables by a unique key and report changed, added, and removed rows.

Your data stays in this browser tool. No account or upload to a processing service required.

Instructions

  1. Paste both tables with matching header names.
  2. Select the key column number in the first table, click Compare tables, and download the change report.

Understanding your result

A changed record means the same unique key exists in both tables but at least one compared field differs. Added and removed records refer to keys present in only one version. Treat the report as a review list before changing the source records.

What to do if you have a problem

If comparison is rejected, find blank or repeated keys first. If many unexpected changes appear, inspect delimiter settings, header spelling and formatting differences such as padded IDs. Exact text comparison can flag a display change even when a human considers the values equivalent.

What to know before using the result

Maximum 2 MB and 20,000 rows per input and output, including headers. Keys must be unique and nonblank. Comparisons are exact and case-sensitive. Reordered columns are matched by header name. Added/removed rows are represented as JSON arrays.

These tools work with pasted text or supported CSV files rather than Excel workbook files. CSV exports contain values and do not preserve workbook formatting, formulas or multiple worksheets. Formula builders produce formula text to use in Excel. Data processing runs in the browser tool.

Try an example

ID,Name,City
1,Alice,Dublin
2,Bob,Cork

Summary

Use the changed, added and removed records as a review list for the two table versions.

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