CSV Repair Kit

Runs in your browser

Compare CSV Files

Diff two CSV files by ID, SKU, email, or any key column.

Your files never leave your device.

Original file

Drop original file

CSV, TSV, or text. Processed locally — the file is never uploaded.

New file

Drop new file

CSV, TSV, or text. Processed locally — the file is never uploaded.

When a visual diff is not enough

Line-oriented diffs break as soon as a row is inserted. CSV comparison needs a business key: customer ID, SKU, email, ISBN. This tool indexes both files on that column and classifies rows as added, removed, modified, or unchanged.

How a modification is detected

After a key matches, every other field is compared as text. Numeric 10 and 10.0 are different strings. That is intentional: it shows what the files actually contain, not a coerced spreadsheet value.

Example

Original:

id,plan
1,free
2,free

New:

id,plan
1,pro
3,free

Result: 1 modified (free → pro), 2 removed, 3 added.

Limitations

Comparison is in-memory. Huge dumps may need filtering first. Composite keys are not concatenated automatically — pick one column, or add a key column before comparing.

FAQ

Which file is “original”?

The left file is the baseline. Added rows exist only on the right. Removed rows exist only on the left. Modified rows share a key but differ in other columns.

What if the key is duplicated?

Only the first row for that key is compared. Duplicate keys are listed so you can clean the file first.

Do headers have to match?

The key is chosen by column index. Align columns before comparing if one export inserted a field.

Related tools