Spreadsheet Diff
Compare two CSV files cell by cell with key-column row matching — highlights added, removed, and changed data
About this tool
The Spreadsheet Diff tool compares two CSV datasets at the cell level, matching rows by a key column you choose (such as an ID, email, or SKU). It shows you exactly which rows were added, removed, or changed — with old and new values side by side.
This is the tool you need when someone sends you an updated spreadsheet and you need to know what actually changed: data migrations, periodic data dumps, configuration exports, or any pair of CSVs that share a key column.
Example: CSV A has 1,Alice,85 and CSV B has 1,Alice,90 with key column 1 (id). The tool shows row 1 as changed: score 85 → 90. If CSV B adds row 6,Frank,82 that isn't in CSV A, it appears as + added.
FAQ
How does the tool match rows between the two CSVs? ›
It uses the key column you select (e.g. column 1 for IDs). Rows with the same key value in both CSVs are paired and compared cell by cell. Rows with a key only in CSV A appear as removed; rows with a key only in CSV B appear as added. When duplicate keys appear in one file, the tool pairs them in order of appearance.
What delimiters are supported? ›
Comma, semicolon, tab, and pipe. The auto-detect mode looks at the first line and picks the delimiter that appears most often. Quoted fields (double quotes) are handled correctly, including embedded delimiters and escaped double-quotes.
How is this different from the Diff Checker or JSON Diff tools? ›
Diff Checker compares plain text line by line and looks for word-level changes — it has no concept of CSV structure or key columns. JSON Diff works on JSON objects using dot-path keys but cannot handle flat CSV data. Spreadsheet Diff is purpose-built for tabular data with cell-level highlighting and key-based row matching, which neither of the other tools provide.
Can I compare files with different column orders or extra columns? ›
Yes. The tool aligns columns by position (column 1, 2, 3…), so both CSVs should have the same column order for a meaningful comparison. Extra columns on one side appear as blank cells on the other side and are highlighted as changes.